Individual or distributed non-saturating magnetic element(s) (referenced herein as NSME) power converters

ABSTRACT

Single, multistage, and distributed magnetic switched and tank resonant power conversion systems use a non saturating magnetic element (NSME). The NSME provide superior protection to conducted lightning transients, superior thermal operating bandwidth, higher magnetizing efficiency, greater flux/power density potential and form factor flexibility when implemented with the disclosed circuit strategies. Output voltage is maintained substantially constant and ripple free in the presence of line and load variations by the action of various feedback strategies. These mechanisms combine to produce compensations by controlling the duration and/or frequency of a switch or switches. A novel function generator implementation supplies a signal which is a function of magnetic flux tracking, AC line phasing, and output voltage feedback to provide output regulation, active ripple rejection, and power factor correction to the AC line.

CROSS REFERENCE APPLICATIONS

This application is a divisional application of application Ser. No.09/410,849 filed Oct. 1, 1999 and issued as U.S. Pat. No. 6,272,025 onAug. 7, 2001.

FIELD OF INVENTION

The present invention relates to converters, power supplies, moreparticularly, to single, or multi stage, AC/DC or DC/DC isolated andnon-isolated push-pull converters including but not limited to, forward,flyback, buck, boost, push pull, and resonant mode converters, and powersupplies, having individual or distributed NSME with high speed FETswitching and efficient flyback management and or having input PFC(power factor correction) and input protection from lightningtransients. The invention also allows the magnetic element(s) bedistributed to accommodate packaging restrictions, multiple secondarywindings, or operation at very high winding voltages.

BACKGROUND OF THE INVENTION

There are several basic topologies commonly used to implement switchingconverters.

A DC-DC converter is a device that converts a DC voltage at one level toa DC voltage at another level. The converter typically includes amagnetic element having primary and secondary windings wound around itto form a transformer. By opening and closing the primary circuit atappropriate intervals control over the energy transfer between thewindings occurs. The magnetic element provides an alternating voltageand current whose amplitude can be adjusted by changing the number andratio of turns in each set of the windings. The magnetic elementprovides galvanic isolation between the input and the output of theconverter.

One of the topologies is the push-pull converter. The output signal isthe output of an IC network that switches the transistors alternately“on” and “off”. High frequency square waves on the transistor outputdrive the magnetic element into AC (alternating current) bias. Theisolated secondary outputs a wave that is rectified to produce DC(direct current). The push-pull converters generally have morecomponents as compared to other topologies. The push-pull approach makesefficient use of the magnetic element by producing AC bias, but suffersfrom high parts count, thermal derating, oversized magnetics, andelaborate core reset schemes. The destructive fly-back voltagesoccurring across the switches are controlled through the use ofdissipative snubber networks positioned across the primary switches.Another of the topologies is the forward converter. When the primary ofthe forward converter is energized, energy is immediately transferred tothe secondary winding. In addition to the aforementioned issues theforward converter suffers from inefficient (dc bias) use of the magneticelement. The prior art power supplies use high permeability gappedferrite magnetic elements. These are well known in the art and arewidely used. The magnetics of the prior art power supplies are generallydesigned for twice the required power rating and require complex methodsto reset and cool the magnetic elements resulting in increased costs andlimited operating temperatures. This is because high permeabilitymagnetic elements saturate during operation producing heat in the core,which increases permeability and lowers the saturation threshold. Thisproduces runaway heating, current spikes and/or large leakage currentsin the air gap, reduced efficiency, and ultimately less power at highertemperatures and/or high load. The overall effects are, lowerefficiency, lower power density, and forced air/heatsink dependantsupplies that require over-rated ferrite magnetic elements for a givenoutput over time, temperature, and loading.

IMPROVEMENTS

The combined improvements of the invention translate to higher systemefficiencies, higher power densities, lower operating temperatures, and,improved thermal tolerance thereby reducing or eliminating the need forforced air cooling per unit output. The non-saturating magneticproperties are relatively insensitive to temperature (see FIG. 17), thusallowing the converter to operate over a greater temperature range. Inpractice, the operating temperature for the NSME is limited to 200 C. bywire/core insulation; the non-saturating magnetic material remainsoperable to near its Curie temperature of 500 C.

What are needed are converters having circuit strategies that makeadvantageous use of individual and distributed NSME.

What are needed are converters having buffer circuits that provide fast,low impedance critically damped switching of the main FET's.

What are needed are converters that incorporate efficient multiple“stress-less” flyback management techniques to rectify and criticallydamp excessive node voltages across converter switches. What are neededare converters having flux feedback frequency modulation.

What are needed are converters that correct AC power factor.

What is needed are converters that meet or exceed class B conducted EMIrequirements.

What are needed are converters tolerant of lightning and harsh thermalenvironments. The present invention addresses these and more.

SUMMARY OF THE INVENTION

The main aspect of the present invention is to implement convertershaving circuit strategies that make advantageous use of individual anddistributed NSME for the achievement of the key performance enhancementsdisclosed herein.

Another aspect of the present invention is to provide unique resonanttank circuit converter strategies with individual and distributed NSMEthat make use of higher primary circuit voltage excursions in theproduction of high frequency/high density magnetic flux.

Another aspect of the present invention is a high energy density singlestage frequency controlled resonant tank converter topology enabled bythe use of individual and distributed NSME. Another aspect of thepresent invention is to provide a converter design that utilizes a FETdrive technique consisting of an ultra fast, low RDS on N-channel FETfor charging the main FET gate and an ultra fast P-channel transistorfor discharging the main FET gate.

Another aspect of the present invention is to provide converters thatincorporate efficient multiple “stress-less” flyback managementtechniques to rectify and critically damp excessive node voltages acrossconverter switches.

Another aspect of the present invention is to provide a converter havingcore (flux) synchronized zero crossing frequency modulation.

Another aspect of the present invention is to present a high powerfactor to the AC line.

Another aspect of the present invention is to provide protection fromhigh voltage (input line) transients.

Another aspect of the present invention is to combine distributedmagnetics advantageously with the other converter aspects.

Another aspect of the present invention is active ripple rejectionprovided by several high-gain high-speed isolated control and feedbacksystems.

Other aspects of this invention will appear from the followingdescription and appended claims, reference being made to theaccompanying drawings forming a part of this specification wherein likereference characters designate corresponding parts in the several views.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1 and 1A is a schematic diagram of a two-stage power factorcorrected AC to DC isolated output converter embodiment of theinvention.

FIGS. 2 is a schematic diagram of a single stage DC to AC converterembodiment with isolated output sub-circuit DCAC1.

FIGS. 3 and 3A is a schematic diagram of a three stage AC to DC isolatedoutput converter embodiment of the invention.

FIG. 4 is a schematic diagram of a power factor corrected single stageAC to DC converter sub-circuit ACDFPF.

FIG. 5 is a graph comparing typical winding currents in saturating andnon-saturating magnetics of equal inductance.

FIG. 6 is a schematic for a non-isolated low side switch buck convertersub-circuit NILBK.

FIG. 7 is the preferred embodiment schematic for a tank coupled singlestage converter sub-circuit TCSSC.

FIG. 8 is a schematic for a tank coupled totem pole convertersub-circuit TCTP.

FIG. 9 is a block diagram for a single stage non-isolated DC to DC boostconverter NILSBST.

FIG. 10 is a schematic for a two stage isolated DC to DC boostcontrolled push-pull converter BSTPP.

FIG. 11 is a graph of permeability as a function of temperature fortypical prior art magnetic element material.

FIG. 12 is a graph of flux density as a function of temperature fortypical prior art magnetic element material.

FIG. 12A is a graph of magnetic element losses for various fluxdensities and operating frequencies typical of prior art magneticelement material.

FIG. 13 is a graph showing standard switching losses.

FIG. 14 is a graph showing lower switching losses of the invention.

FIG. 15 is a graph showing the magnetizing curve (BH) for the NSMEmaterial.

FIG. 16 is a graph of magnetic element losses for various flux densitiesand operating frequencies of the NSME material.

FIG. 17 is a graph of permeability as a function of temperature for theNSME.

FIG. 18 is a schematic representation of the boost NSME sub-circuitPFT1.

FIG. 18A is a schematic representation of the NSME sub-circuit PFT1A.

FIG. 18B is a schematic representation of the non-saturating twoterminal NSME sub-circuit BL1.

FIG. 18C is a schematic diagram of the NSME implemented as distributedmagnetic assembly PFT1D.

FIG. 19 is a schematic representation of the push-pull NSME sub-circuitPPT1.

FIG. 19A is a schematic representation of the alternate push-pull NSMEsub-circuit PPT1A.

FIG. 20 is a schematic diagram of the NSME input transient protectionand line filter sub-circuit LL.

FIG. 21 is a schematic diagram of the alternate NSME input transientprotection and line filter sub-circuit LLA.

FIG. 22 is a schematic diagram of the AC line rectifier sub-circuit BR.

FIG. 23 is a schematic diagram of the power factor controllersub-circuit PFA.

FIG. 24 is a schematic diagram of the alternate power factor correctingboost control element sub-circuit PFB.

FIG. 25 is a schematic diagram of the output rectifier and filtersub-circuit OUTA.

FIG. 25A is a schematic diagram of an alternate rectifier sub-circuitOUTB.

FIG. 25B is a schematic diagram of an alternate final output rectifierand filter sub-circuit OUTBB.

FIG. 26 is a schematic diagram of the floating 18_Volt DC control powersub-circuit CP.

FIG. 27 is a schematic diagram of the alternate floating 18_Volt DCpush-pull control power sub-circuit CPA.

FIG. 28 is a schematic diagram of the over temperature protectionsub-circuit OTP.

FIG. 29 is a schematic diagram of the high-speed low impedance buffersub-circuit AMP, AMP1, AMP2 and AMP3.

FIG. 30 is a schematic diagram of the main switch snubber sub-circuitSN.

FIG. 30A is a schematic diagram of the main switch rectifying diodesnubber sub-circuit DSN.

FIG. 31 is a schematic diagram of the alternate snubber sub-circuit SNA.

FIG. 32 is a schematic diagram of the mirror snubber sub-circuit SNB.

FIG. 33 is a schematic diagram of the pulse-width/Frequency modulatorsub-circuit PWFM.

FIG. 34 is an oscillograph of node voltages measured during operation ofsub-circuit PWFM (FIG. 33).

FIG. 35 is an oscillograph of the primary tank voltage measured duringoperation of sub-circuit TCTP (FIG. 8).

FIG. 36 is a schematic diagram of the non-isolated 18-Volt DC controlpower sub-circuit REG.

FIG. 37 is a schematic for a non-isolated high-side switch buckconverter sub-circuit HSBK.

FIG. 38 is a schematic for the low-side buck regulated two-stageconverter embodiment with isolated push-pull output sub-circuit LSBKPP.

FIG. 39 is a schematic for an alternate isolated two-stage low-sideswitch buck converter sub-circuit LSBKPPBR.

FIG. 40 is a schematic diagram of the over voltage feed back sub-circuitIPFFB.

FIG. 40A is a schematic diagram of the non-isolated boost output voltagefeedback sub-circuit FBA.

FIG. 40B is a schematic diagram of the isolated output voltage feedbacksub-circuit IFB.

FIG. 40C is a schematic diagram of the alternate isolated over voltagefeedback sub-circuit IOVFB.

FIG. 41 is a schematic diagram of the non-isolated output voltagefeedback sub-circuit FBI.

FIG. 42 is a schematic diagram of an over voltage protection sub-circuitOVP.

FIG. 42A is a schematic diagram of the isolated over voltage feedbacksub-circuit OVP1.

FIG. 42B is a schematic diagram of the over voltage protectionsub-circuit OVP2.

FIG. 42C is a schematic diagram of the isolated over voltage feedbacksub-circuit OVP3.

FIG. 43 is a schematic diagram of the Push-pull oscillator sub-circuitPPG.

Before explaining the disclosed embodiments of the present invention indetail, it is to be understood that:

The invention is not limited in its application to the details of theparticular arrangements shown or described, since the invention iscapable of other embodiments.

The expression “distributed magnetic(s)” refers to the configuration ofmultiple magnetic elements that share a single series coupled primarywinding to induce isolated output currents from multiple series orparallel secondary windings.

Also, the terminology used herein is for the purpose of description notlimitation.

DESCRIPTION OF THE PREFERRED EMBODIMENT

In this and other descriptions contained herein, the following symbolsshall have the meanings attributed to them: “+” shall indicate a seriesconnection, such as resistor A in series with resistor B shown as “A+B”.“||” Shall indicate a parallel connection, such as resistor A inparallel with resistor B shown as “A||B”.

Referring first to FIG. 7, a schematic diagram of the preferredembodiment of the invention.

FIG. 7 is a schematic of the preferred embodiment of a tank coupledsingle stage converter sub-circuit TCSSC. Sub-circuit TCSSC consists ofresistor R20 and RLOAD, capacitor C10, transistors Q21 and Q11,sub-circuit CP (FIG. 26), sub-circuit PFT1 (FIG. 18), sub-circuit OUTA(FIG. 25), sub-circuit AMP (FIG. 29), sub-circuit IFB (FIG. 40B) andsub-circuit PWFM (FIG. 33).

FIG. 7 Table Element Value/part number R20 1k ohms R61 2k ohms Q21TST541 U12 4N29 Q11 IRFP460 C10 1.8 uf

TCSSC can be configured to operate as an AC-DC converter, a DC-DCconverter, a DC-AC converter, and an AC-AC converter. Sub-circuit TCSSCconsists of resistor R20 and RLOAD, capacitor C10, switches Q11 and Q21,opto-isolator U12, sub-circuit PFT1 (FIG. 18), sub-circuit OUTA (FIG.25), sub-circuit CP (FIG. 26) , sub-circuit AMP (FIG. 29) , sub-circuitIFB (FIG. 40B) and sub-circuit PWFM (FIG. 33). External power sourceVBAT connects to pins DCIN+ and DCIN−. Source power may also be derivedfrom rectified AC line voltage such as FIG. 20 or FIG. 21 to form asingle stage power factor corrected AC to DC converter with isolatedoutput. From DCIN+ resistor R20 connects to sub-circuit CP pin CP+,sub-circuit AMP pin GA+, U12 LED anode and to sub-circuit PWFM pinPWFM+. Resistor R20 provides startup power to the converter until thecontrol supply regulator sub-circuit CP reaches the desired 18-voltoutput. VBAT negative is the ground return node connects to sub-circuitPWFM pin PWFM0, Q11 source, sub-circuit AMP pin GA0, sub-circuit CP pinCT0, pin DCIN− and sub-circuit PFT1 pin S1CT. Magnetic element windingnode S1H of sub-circuit PFT1 is connected to CP pin CT1A. Magneticelement winding node S1L of sub-circuit PFT1 is connected to CP pinCT2A. Sub-circuit PWFM is designed as a constant 50% duty-cycle variablefrequency generator. Sub-circuit PWFM Clock output pin CLK is connectedto input of buffer sub-circuit AMP pin GA1. The output of buffersub-circuit AMP pin GA2 is connected to the gate of Q11 and R21.Resistor R21 is connected to the cathode of U12 LED. The emitter of Q21and drain of Q11 is connected to sub-circuit PFT1 pin P1A. Pin P1B ofsub-circuit PFT1 is connected through tank capacitor C10 to node DCIN+,Q21 collector and through resistor R61 to U12 phototransistor collector.The emitter of U12 phototransistor is connected to the base of Q21. WithPWFM pin CLK high transistor Q11 conducts charging capacitor C10 throughNSME PFT1 from VBAT storing energy in PFT1. Sub-circuit PWFM switchesCLK low, Q11 turns “off”. With CLK low LED of U12 is turned “on”injecting base current into Q21. With transistor Q21 “on” the tankcircuit is completed, allowing capacitor C10 to discharge into NSME PFT1winding 100 (FIG. 18). Now the energy not transferred into the load isreleased from NSME PFT1 into the now forward biased NPN switch Q21 backinto capacitor C10. Thus any energy not used by the secondary loadremains in the tank coupled primary circuit (winding 100). When theswitching occurs at the resonant frequency, high voltages oscillatebetween C10 and winding 100 creating high flux density AC excursions inPFT1. C10 and PFT1 exchange variable AC currents whose magnitude iscontrolled by frequency modulation scheme IFB and PWFM. The largeprimary voltage generates large, high frequency biases in the NSME PFT1thereby producing high flux density AC excursions to be harvested bysecondary windings 102 and 103 (FIG. 18) to support a load or rectifiersub-circuit OUTA. Magnetic element winding node S2H of sub-circuit PFT1is connected to OUTA pin C7B. Magnetic element winding node S2L ofsub-circuit PFT1 is connected to OUTA C8B. Magnetic element winding nodeS2CT of sub-circuit PFT1 is connected to OUTA pin OUT−. Node OUT− isconnected to RLOAD, pin B− and to sub-circuit IFB pin OUT−. Rectifiedpower is delivered to pin OUT+ of OUTA and is connected to RLOAD, pin B+and to sub-circuit IFB pin OUT+. Sub-circuit IFB provides the isolatedfeedback signal to the sub-circuit PWFM. Frequency control pin FM1 ofsub-circuit PWFM is connected to sub-circuit IFB pin FBE. Internalreference pin REF of sub-circuit PWFM is connected to sub-circuit IFBpin FBC. PWFM is designed to operate at the resonate frequency of thetank (2*pi*(square root (C10*inductance of 100 (FIG. 18)). Whensub-circuit IFB senses the converter output is at the target voltage,current from PWFM pin REF is injected into FM1. Injecting current intoFM1 commands the PWFM to a lower clock frequency pin CLK. Driving thetank out of resonance reduces the amount of energy added to the tankthus reducing the converter output voltage. In the event the feedbacksignal from IFB commands the PWFM off or 0 Hz, i.e.: at no load, allprimary activity stops. The input current from VBAT may be steady stateor variable DC. When TCSSC is operated from rectified AC (sub-circuit LLFIG. 20), high input (line) power factor and input transient protectionis achieved. The primary and secondary currents of PFT1 are sinusoidaland free of edge transitions making the converter very quiet. Inaddition the switches Q11 and Q21 are never exposed to the largecirculating voltage induced in the tank (See FIG. 35). This allows theuse of lower voltage switches in the design thereby reducing losses andincreasing the MTBF. Sub-circuit TCSSC takes advantage of the desirableproperties of the NSME in this converter topology. TCSSC is well suitedfor implementation with distributed NSME PFT1D (FIG. 18C). Thiscombination exemplifies how distributed magnetics enable advantageoushigh voltage converter design variations that support form factorflexibility and multiple parallel secondary outputs from series coupledvoltage divided primary windings across multiple NSME. This magneticstrategy is useful in addressing wire/core insulation, form factor andpackaging limitations, circuit complexity and manufacturability. Theseconverter strategies are very useful for obtaining isolated high currentdensity output from a high voltage low current series coupled primary.Adjusting the secondary turn's ratio allows TCSSC to generate very largeAC or DC output voltages as well as low-voltage high current outputs.

ADDITIONAL EMBODIMENTS

FIGS. 1 and 1A is a schematic diagram of a two stage power factorcorrected AC to DC converter. The invention is comprised of lineprotection filter sub-circuit LL (FIG. 20) and full-wave rectifiersub-circuit BR (FIG. 22). A power factor corrected regulated boost stagewith sub-circuits PFA2 (FIG. 23), snubber sub-circuit SN (FIG. 30),magnetic element sub-circuit PFT1 (FIG. 18), sub-circuit CP (FIG. 26),buffer sub-circuit AMP (FIG. 29), over temperature sub-circuit OTP (FIG.28), over voltage feedback sub-circuit IPFFB (FIG. 40) and voltagefeedback sub-circuit IFB (FIG. 40B). Start up resistor R2, filtercapacitor C1, PFC capacitor C2, flyback diode D4, switch transistor Q1,hold up capacitors C17 and C16, and resistor R17. An efficient push-pullisolation stage with sub-circuits CPA (FIG. 27), PPG (FIG. 43), AMP1(FIG. 29), AMP2 (FIG. 29), snubber sub-circuits SNB (FIG. 32) and SNA(FIG. 31), resistor Rload, transistors Q6 and Q9, magnetic element PPT1(FIG. 19), and OUTA (FIG. 25).

FIG. 1 Table Element Value/part number C1 0.01 uf C2 1.8 uf R2 100k ohmsD4 8A,600 V Q1 IRFP 460 C17 100 uf C16 100 uf R17 375k ohms Q6 FS14SM-18A Q9 FS 14SM-18A

In the two-stage converter the primary side voltage to the secondpush-pull output stage is modulated by the power factor corrected input(boost) stage. Each stage can comprise of individual and distributedNSME. A graph of B-H hysteresis for the non-saturating magnetics is setforth in FIG. 15. Although the following description is in terms ofparticular converter topologies, i.e., flyback controlled primary andconstant duty cycle push pull secondary, number of outputs, the style,and arrangement of the several topologies are offered by way of example,not limitation. In addition non-saturating magnetics BL1, PFT1, and PPT1may be implemented as distributed NSME. As an example PFT1 is shown as adistributed magnetic PFT1A (FIG. 18C). Distributed magnetics enableadvantageous high voltage converter design variations that support formfactor flexibility and multiple parallel secondary outputs from seriescoupled voltage divided primary windings across multiple NSME. Thenegative of the hold-up capacitor(s) [C17||C16] is connected to bridgepositive. This allows the rectified line voltage to be excluded from theboost voltage in the hold-up capacitor(s). This, in turn, allows directregulation of the push-pull stage from the boost (PFC) stage. Thiseliminates the typical PWM control of the oversized thermally deratedtransformer and many sub-circuit components from the known art. AC lineis connected to sub-circuit LL (FIG. 20) between pins LL1 and LL2.AC/earth ground is connected to node LL0. The filtered and voltagelimited AC line appears on node/pin LL5 of sub-circuit LL and connectedto node BR1 of bridge rectifier sub-circuit BR (FIG. 22). The neutral/ACreturn leg of the filtered and voltage limited AC appears on pin LL6 ofsub-circuit LL is connected to input pin BR2 of BR. The line voltage isfull-wave rectified and is converted to a positive haversine appearingon node BR+ of sub-circuit BR (FIG. 22). Start up resistor R2 connectsBR+ to sub-circuit CP pin CP+. Node CP+ connects to pins PFA+ of controlelement sub-circuit PFA (FIG. 23) and over temperature switchsub-circuit OTP (FIG. 28) pin GAP. Resistor R2 provides start up powerto the control element until the rectifier/regulator CP is at fulloutput. Node S1H from PFT1 is connected to node PFVC of sub-circuit PFA.The zero crossings of the core are sensed when the voltage at S1H is atzero. The core zero crossings are used to reset the PFC and start a newcycle. The positive node of the DC side of bridge BR+ is connectedthrough capacitor C2 to BR−. C2 is selected for various line and loadconditions to de-couple switching current from the line improving powerfactor while reducing line harmonics and EMI. Primary of NSMEsub-circuit PFT1 (FIG. 18) pins P1B and S2CT connects to pin SNL1 ofsnubber sub-circuit SN (FIG. 30), to sub-circuit BR pin BR+ and connectsto pin BR+ (FIG. 1A). The return line for the rectified AC power BR− isconnected to the following pins: BR− of sub-circuit BR, PFA pin BR−,sub-circuit AMP pin GA0, output switch Q1 source, capacitor C2,sub-circuit CP pin CT0 sub-circuit PFT1 pin S1CT and CT20 through EMIfilter capacitor C1 to earth ground node LL0. Pin BR+ from FIG. 1 isconnected to FIG. 1A sub-circuits CPA pin SN pin SNL1, sub-circuit PFT1pin P1B, and sub-circuit PFT1 pin S2CT. Pin BR+ continues to FIG. 1Aconnecting to sub-circuit CPA pin CT20, PPG (FIG. 43) pin PPG0,sub-circuit AMP1 pin GA0, sub-circuit AMP2 pin GA0, sub-circuit IPFFBpin PF−, Capacitor [C16||C17||resistor R17], transistor Q6 source,transistor Q9 source, sub-circuit SNA pin SNA2 and sub-circuit SNB pinSNB2. The drain of output switch Q1 is connected to diode D4 anode,sub-circuit SNB pin SNL2, and sub-circuit PFT1 pin P1A and sub-circuitSN pin SNL2. Snubber network SN reduces the high voltage stress to Q1until flyback diode D4 begins conduction. Line coupled, power factorcorrected boost regulated output voltage of the AC to DC converter stage(FIG. 1) appears on node PF+. Addition efficiency may be realized byconnecting sub-circuit DSN (FIG. 30A) in parallel with D4. The regulatedboost output PF+ connects to the following: sub-circuit SN pin SNOUT,sub-circuit DSN pin SNOUT and diode D4 cathode. Node PF+ also connectson FIG. 1A to capacitors [C16||C17||R17], sub-circuit IPFFB (FIG. 40)pin PF+, sub-circuit PPT1 (FIG. 19) pin P2CT, snubber sub-circuit SNA(FIG. 31) pin SNA3, and snubber SNB (FIG. 32) pin SNB3. Magnetic elementwinding pin S1H of sub-circuit PFT1 is connected to CP pin CTLA and pinPFVC of sub-circuit PFA. Magnetic element winding node S1L ofsub-circuit PFT1 is connected to CP pin CT2A. Magnetic element windingnode S2H of sub-circuit PFT1 is connected to pin 10FIG. 1A then to CPApin CTLB. Magnetic element winding node S2L of sub-circuit PFT1 isconnected to pin 12FIG. 1A then to CPA pin CT2B. Sub-circuit PFA usingthe AC line phase, load voltage, and magnetic element feedback,generates a command pulse PFCLK. Pin PFCLK of sub-circuit PFA (FIG. 23)is connected to the input of buffer amplifier pin GA1 of sub-circuitAMP1 (FIG. 29). Buffered high-speed gate drive output pin GA2 ofsub-circuit AMP is connected to gate of switch FET Q1. The bufferingprovided by AMP shortens switch Q1 ON and OFF times greatly reducingswitch losses (see FIGS. 13 & 14). The source of Q1 with pin GA0 isconnected to return node BR−. Power to sub-circuit AMP is connected topin GA+ from sub-circuit OTP pin TS+. Thermal switch THS1 is connectedto Q1. In the event the case of Q1 reaches approximately 105 C. THS1opens removing power to sub-circuit AMP, safely shutting down the first(input) stage. Normal operation resumes after the switch temperaturedrops 20-30 deg. C. closing THS1. Drain of output switch Q1 is connectedto primary winding pin P1A of non-saturating magnetic sub-circuit PFT1(FIG. 18) and to pin SNL2 of snubber sub-circuit SN (FIG. 30). Referencevoltage from PFC sub-circuit PFA pin PFA2 is connected to feedbacknetworks sub-circuit IPFFB pin FBC and to sub-circuit IFB pin FBC.Control current feedback networks is summed at node PF1 of sub-circuitPFA. Pin PF1 is connected to feed back networks sub-circuit IPFFB pinFBE and to sub-circuit IFB pin FBE. Constant frequency/duty-cyclenon-overlapping two-phase generator sub-circuit PPG (FIG. 431A)generates the drive for the push-pull output stage. Phase one output pinPH1 is connected to sub-circuit AMP1 pin GA1, second phase output pinPH2 is connected to sub-circuit AMP2 pin GA1. Output of amplifier buffersub-circuit AMP1 pin GAP2 connects to gate of push-pull output switchQ6. Output of amplifier buffer sub-circuit AMP2 pin GAP2 connects togate of push-pull output switch Q9. The buffering currents from AMP1 andAMP2 provide fast, low impedance critically damped switching to Q6 andQ9 greatly reducing ON-OFF transition time and switching losses.Regulated 18-volt power from sub-circuit CPA (FIG. 1A) pin CP2+ isconnected to amplifier buffer sub-circuit AMP1 pin GA+, amplifier buffersub-circuit AMP2 pin GA+ and sub-circuit PPG pin PPG+. Drain oftransistor Q6 is connected to snubber network sub-circuit SNB pin SNB1and to non-saturating center tapped primary magnetic element sub-circuitPPT1 pin P2H. Drain of transistor Q9 is connected to snubber networksub-circuit SNA (FIG. 31) pin SNA1 and sub-circuit PPT1 pin P2L. Sourceof transistor Q6 is connected to snubber network sub-circuit SNB pinSNB2, transistor Q9 source, sub-circuit SNA pin SNA2 and to return nodeBR+. Isolated output of NSME sub-circuit PPT1 pin SH connects to Pin C7Bof rectifier sub-circuit OUTA (FIG. 25A), pin SL connects to sub-circuitOUTA C8B. Center tap of PPT1 pin SCT is the output return or negativenode OUT− it connects to sub-circuit OUTA pin OUT− and sub-circuit IFB(FIG. 40B) pin OUT− and RLOAD. Converter positive output fromsub-circuit OUTA pin OUT+ is connected to RLOAD and sub-circuit IFB pinOUT+. FIG. 1 elements LL1, BR, PFA, AMP, Q1, IPFFB, IFB and PFT1 (inputstage) perform power factor corrected AC to DC conversion. The regulatedhigh voltage output of this converter supplies the efficient fixedfrequency/duty-cycle push-pull stage comprising PPG, AMP1, AMP2, Q6, Q9,PPT1 and OUTA (FIG. 1A). Magnetic element sub-circuit PPT1 providesgalvanic isolation and minimal voltage overshoot and ripple in thesecondary thus minimizing filtering requirements of the rectifiersub-circuit OUTA. Five volt reference output from sub-circuit PFA pinPFA2 connects to pin 15 then to FIG. 1A sub-circuit IPFFB pin FBC and tosub-circuit IFB pin FBC. Pulse width control input from sub-circuit PFApin PF1 connects to pin 14 then to FIG. 1A sub-circuit IPFFB pin FBE andto sub-circuit IFB pin FBE. Sub-circuit IFB provides high-speed feedbackto the AC DC converter, the speed of the boost stage provides preciseoutput voltage regulation and active ripple rejection. In the event ofsudden line or load changes, sub-circuit IPFFB corrects the internalboost to maintain regulation at the isolated output. Remote load sensingand other feedback schemes known in the art may be implemented withsub-circuit IPFFB. This configuration provides power factor correctedinput transient protection, rapid line-load response, excellentregulation, isolated output and quiet efficient operation at hightemperatures.

FIG. 2 is a schematic diagram of an embodiment of a DC to AC converter.The invention DCAC1 is an efficient push-pull converter. Comprised ofsub-circuits PPG (FIG. 43), AMP1 (FIG. 29), AMP2 (FIG. 29), SNB (FIG.32), SNA (FIG. 31), PPT1 (FIG. 19) and OUTA (FIG. 25), switches Q6 andQ9.

FIG. 2 Table Element Value/part number Q6 FS 14SM-18A Q9 FS 14SM-18A

Converter ACDC1 accepts variable DC voltage and efficiently converts itto a variable AC voltage output at a fixed frequency. Variable frequencyoperation may be achieved by simple changes to PPG. In this embodimentfixed frequency operation is required. The magnetic element comprisesnon-saturating magnetics. A graph of B-H hysteresis for thenon-saturating magnetics is set forth in FIG. 15. Variable DC voltage isapplied to pin DC+. The pin DC+ connects to the following, sub-circuitPPT1 (FIG. 19) pin P2CT, snubber sub-circuit SNA (FIG. 31) pin SNA3, andsnubber SNB (FIG. 32) pin SNB3. Constant frequency non-overlappingtwo-phase generator sub-circuit PPG (FIG. 43) generates the drive forthe push-pull output switches. Phase one output pin PH1 is connected tosub-circuit AMP1 pin GA1, the second phase output pin PH2 is connectedto sub-circuit AMP2 pin GA1. Output of amplifier buffer sub-circuit AMP1pin GAP2 connects to gate of push-pull output switch Q6. Output ofamplifier buffer sub-circuit AMP2 pin GAP2 connects to gate of push-pulloutput switch Q9. The buffering provided by AMP1 and AMP2 shortensswitch Q1 ON and OFF times greatly reducing switching losses (See FIGS.13 and 14). External regulated 18-volt power from pin P18V connected toamplifier buffer sub-circuit AMP1 pin GA+, amplifier buffer sub-circuitAMP2 pin GA+ and sub-circuit PPG pin PPG+. Drain of transistor Q6 isconnected to snubber network sub-circuit SNB pin SNB1 and tonon-saturating center tapped primary magnetic element sub-circuit PPT1pin P2H. Drain of transistor Q9 is connected to snubber networksub-circuit SNA (FIG. 31) pin SNA1 and sub-circuit PPT1 pin P2L. Sourceof transistor Q6 is connected to snubber network sub-circuit SNB pinSNB2, transistor Q9 source, sub-circuit SNA pin SNA2, sub-circuit AMP1pin GA0, sub-circuit AMP2 pin GA0, sub-circuit PPG pin PPG0, and toreturn pin DC−. AC output of NSME sub-circuit PPT1 pin SH connects toPin ACH, pin SL connects to pin ACL. Center tap of PPT1 pin SCT isconnected to pin AC0. Magnetic element sub-circuit PPT1 providesgalvanic isolation and minimal voltage overshoot in the secondary thusminimizing filtering requirements if a rectifier assembly is attached.Sub-circuit DCAC1 may be used as a stand-alone converter or as a fastquiet efficient stage in a multi stage converter system. Sub-circuitDCAC1 achieves isolated output, quiet operation, efficient conversion,and operation at high and low temperatures.

FIGS. 3 and 3A is a three-stage version of the present invention. Thearrangement is comprised of an AC-DC or DC-DC boost converter stage,DC-DC forward converter stage, and a push-pull stage. This systemreduces losses by combining low current buck regulation, bufferedswitching, rectified snubbering, and NSME in each stage. A power factorcorrected boost stage is used to assure that any load connected to theconverter looks like a resistive load to the AC line, eliminatingundesirable harmonic and displacement currents in the AC power line.NSME having a lower permeability compared to the prior art are used tominimize magnetizing losses, improve coupling efficiency, minimizemagnetic element heating, eliminate saturated core current spikes/gapleakage, reduce parts count, reduce thermal deterioration, and increaseMTBF (mean time before failure). The invention also uses an emitterfollower circuit with a high speed switching FET to slew the main FETgate rapidly. The use of non-saturating magnetics allows operation athigher voltages, which proportionally lowers current further reducingswitch, magnetic element, and conductor losses due to I²R heating. Highvoltage FET switches have the added benefit of lower gate capacitance,which translates to faster switching. At turn on, the n-channel gatedrive FET quickly charges the main FET gate. At turn off, a PNPDarlington transistor switch quickly discharges the main FET gate. Theflyback effect in the PFC stage is managed by use of rectifying RCnetworks positioned across the output diode with an additional capacitorcoupled diode across the switched magnetic element to decouple andfurther dampen the inductive flyback.

FIG. 3 and FIG. 3A is a schematic diagram of a three stage AC to DCconverter. FIGS. 3 and 3A is a three-stage version of the presentinvention. The arrangement is comprised of an AC-DC or DC-DC boostconverter stage, DC-DC forward converter stage, and a push-pull stage.This system reduces losses by combining low current buck regulation,buffered switching, rectified snubbering, and NSME in each stage. Apower factor corrected boost stage is used to assure that any loadconnected to the converter looks like a resistive load to the AC line,eliminating undesirable harmonic and displacement currents in the ACpower line. NSME having a lower permeability compared to the prior artare used to minimize magnetizing losses, improve coupling efficiency,minimize magnetic element heating, eliminate saturated core currentspikes/gap leakage, reduce parts count, reduce thermal deterioration,and increase MTBF (mean time before failure). The invention also uses anemitter follower circuit with a high speed switching FET to slew themain FET gate rapidly. The use of non-saturating magnetics allowsoperation at higher voltages, which proportionally lowers currentfurther reducing switch, magnetic element, and conductor losses due toI²R heating. High voltage FET switches have the added benefit of lowergate capacitance, which translates to faster switching. At turn on, then-channel gate drive FET quickly charges the main FET gate. At turn off,a PNP Darlington transistor switch quickly discharges the main FET gate.The flyback effect in the PFC stage is managed by use of rectifying RCnetworks positioned across the output diode with an additional capacitorcoupled diode across the switched magnetic element to decouple andfurther dampen the inductive flyback. The invention is comprised of apower factor corrected regulating boost stage with line protectionfilter sub-circuit LL1 (FIG. 21) and full-wave rectifier sub-circuit BR(FIG. 22) and capacitors C1 and C2. Sub-circuits PFB (FIG. 24), resistorR2, rectifier CP (FIG. 26), magnetic element PFT1 (FIG. 18), overtemperature protection OTP (FIG. 28) snubber SN (FIG. 30) gate bufferAMP (FIG. 29), switch transistors Q1, flyback diode D4, holdupcapacitors C17 and C16, bleed resistor R17, and voltage feedbacksub-circuit FBA (FIG. 40A). An efficient second pre-regulating buckstage with sub-circuits PWFM (FIG. 33) , current sense resistor R26,rectifier CPA (FIG. 27), magnetic element BL1 (FIG. 18B), over voltageprotection OVP (FIG. 42), IPFFB (FIG. 40) gate buffer AMP3 (FIG. 29),switch transistor Q2, flyback diode D70, storage capacitor C4, andvoltage feedback sub-circuit IFB (FIG. 40B).

An efficient third push-pull isolation stage with sub-circuits CPA (FIG.27), two-phase generator PPG (FIG. 43), gate buffers AMP1 (FIG. 29) andAMP2 (FIG. 29), switch transistors Q6, and Q9, snubbers SNA (FIG. 31)and SNB (FIG. 32), magnetic element PPT1 (FIG. 19) and rectifier OUTA(FIG. 25).

FIG. 3 3A Table Element Value/part number C1 .01 uf C2 1.8 uf R2 100kohms D4 STA1206 DI R17 375 k ohms Q1 IRFP460 C16 100 uf C17 100 uf R26.05 ohms D70 STA1206 DI Q2 IRFP460 C4 10 uf Q6 FS14Sm-18A Q9 FS14Sm-18A

AC line is connected to sub-circuit LLA (FIG. 21) between pins LL1 andLL2. AC/earth ground is connected to node LL0. The filtered and voltagelimited AC line appears on node/pin LL5 of sub-circuit LLA and connectedto node BR1 of bridge rectifier sub-circuit BR. The neutral/AC returnleg of the filtered and voltage limited AC appears on pin LL6 ofsub-circuit LL is connected to input pin BR2 of BR. The line voltage isfull-wave rectified and is converted to a positive haversine appearingon node BR+ of sub-circuit BR. Start up resistor R2 connects BR+ tosub-circuit CP pin CP+. Node CP+ connects to pins PFA+ of controlelement sub-9 circuit PFB and over temperature switch sub-circuit OTPpin GAP. Resistor R2 provides start up power to the control elementuntil the regulator CP is at full output. Node S1H from PFT1 isconnected to pin 31 (FIG. 3) then to pin CT1A of sub-circuit CP and pinPFVC of sub-circuit PFB. The zero crossing of the core bias are sensedwhen the voltage at S1H is at zero relative to BR−. The core zerocrossings are used to reset the PFC and start a new cycle. The positivenode of the DC side of bridge BR+ is connected through capacitor C2 toBR−. Capacitor C2 is selected for various line and load conditions tode-couple switching current from the line improving power factor.Sub-circuit BR pin BR+ connects to pin SNL1 of snubber sub-circuit SN,sub-circuit PFB pin BR+ and pin BR+ (FIG. 3A) then to primary of NSMEsub-circuit PFT1 pin P1B and to sub-circuit OVP pin BR+. The return linefor the rectified AC power is connected to the following pins; BR− ofsub-circuit BR, sub-circuit PFT1 pin S1CT, PFC sub-circuit PFB pin BR−,sub-circuit FBA pin BR−, capacitor C2, sub-circuit CP pin CT0,sub-circuit IPFFB pin FBE, and through EMI filter capacitor C1 to earthground node LL0. Node BR− continues to FIG. 3A connecting to R26,capacitors [C16||C17||R17], sub-circuit OVP pin BR−, sub-circuit PWFMpin PWFM0, sub-circuit AMP3 pin GA0, switch Q2 source. Floating groundnode PF− is connected to magnetic element sub-circuit PFT1 pin S2CT,rectifier sub-circuit CPA pin CT20, generator sub-circuit PPG (FIG. 43)pin PPG0, sub-circuit AMP1 pin GA0, sub-circuit AMP2 pin GA0, capacitorC4, magnetic element BL1 pin, transistor Q6 source, transistor Q9source, sub-circuit SNA pin SNA2 sub-circuit SNB pin SNB2, pin PF− FIG.3 then to sub-circuit IPFFB pin PF−. Drain of output switch Q1 isconnected to diode D4 anode, sub-circuit SN pin SNL2, then to pin 34 ofFIG. 3A then to sub-circuit PFT1 pin P1A. Snubber SN reduces the highvoltage stress to Q1 until flyback diode D4 begins conduction.Additional rectification efficiency and protection is achieved by addingsub-circuit DSN (FIG. 30A) across flyback diode D4. Feedback correctedboost output voltage of the power factor corrected AC to DC converterstage appears across nodes PF+ and PF−. The regulated 385-volt boostoutput node PF+ connects to the following; sub-circuit SN pin SNOUT,diode D4 cathode, sub-circuit IPFFB (FIG. 40) pin PF+, sub-circuit FBApin PF+, then to pin PF+ of FIG. 3A, capacitors [C16||C17||R17],magnetic element sub-circuit PTT1 (FIG. 19) pin P2CT, snubbersub-circuit SNA (FIG. 31) pin SNA3, and snubber SNB (FIG. 32) pin SNB3,sub-circuit OVP pin PF+, capacitor C4 and diode D70 cathode. Magneticelement winding node S1H of sub-circuit PFT1 is connected to pin 31FIG.3 then to sub-circuit CP pin CT1A and pin PFVC of sub-circuit PFB.Magnetic element winding node S1L of sub-circuit PFT1 is connected topin 33FIG. 3 then to sub-circuit CP pin CT2A. Magnetic element windingnode S2H of sub-circuit PFT1 is connected to CPA pin CTLB. Magneticelement winding node S2L of sub-circuit PFT1 is connected to CP pinCT2B. Sub-circuit PFB using feedback from the phase of the AC line, Q1switch current, magnetic bias first stage and output voltage feedbackgenerates a command pulse on pin PFCLK. Pin PFCLK of sub-circuit PFB(FIG. 24) is connected to the input of buffer AMP amplifier pin GA1 ofsub-circuit AMP1. Buffered high-speed low impedance gate drive outputpin GA2 of sub-circuit AMP is connected to gate of switch FET Q1. Thebuffering provided by AMP shortens switch Q1 “ON” and “OFF” timesgreatly reducing switch losses (See FIGS. 13 and 14). The source of Q1is connected to sub-circuit AMP pin GA0, pin 35 of FIG. 3A then tocurrent sense resistor R26 connected to return node BR−. The voltagedeveloped across R26 is fed back to PFB pin PFSC. This signal is used toprotect the switch by reducing the pulse width in response to a low lineor high load induced over current fault. The return line of sub-circuitFBA pin BR− is connected to node BR− and to pin BR− of sub-circuit PFB.This feedback is non-isolated; network values are selected for the firststage to develop a 385-Volt output at PF+. Sub-circuit feedback networkFBA (FIG. 40A) pin PF1 is connected to sub-circuit PFB pin PF1.Controller PFB modulates PFCLK signal to maintain a substantiallyconstant 385-voltage at PF+ independent of line and load conditions. Inthe event of a component failure in sub-circuit FBA the PBF may commandthe converter to very high voltages. Sub-circuit OVP monitors the firststage boost in the event it exceeds 405-volts OVP will clamp the outputof sub-circuit BR causing fuse F1 in sub-circuit LLA to open. Analternate over voltage network OVP1 (FIG. 42A) may replace OVP clampingthe 18-volt control power stopping the boost action of the converterwithout opening the fuse. Sampled converter output at node fromsub-circuit FBA pin PF1 is connected to sub-circuit PFB pin PF1. Thehaversine on BR+ is used with an internal multiplier by PFB to generatevariable width control pulses on pin PFCLK. The high frequencymodulation of switch Q1 makes the load/converter appear resistive to theAC line. Over temperature protection sub-circuit OTP pin TS+ isconnected to sub-circuit AMP pin GA+. Thermal switch THS1 is connectedto Q1. In the event Q1 reaches approximately 105 C. THS1 opens removingpower to sub-circuit AMP, safely shutting down the first stage. Normaloperation resumes after the temperature decreases 20-30 C. closing THS1.The second stage is configured as a buck stage. It accepts the 385-Voltoutput of the first stage. By employing a second floating reference nodePF− energy storage element capacitor C4 the voltage to the finalpush-pull stage may be regulated with minimal loss. Power fromsub-circuit CP pin CP18V+ is connected to pin 30 of FIG. 3A then tosub-circuit PWFM (FIG. 33) pin PWM+ and AMP3 pin GA+. Feedback currentfrom sub-circuit IPFFB pin FBC is connected to pin 36FIG. 3A then tosub-circuit IFB pin FBC and sub-circuit PWFM pin PF1. Sub-circuit IPFFBonly shunts current from this node if the output of the second stage isgreater than 200-volts. When the converter reaches its designed outputvoltage, IFB shunts current from PWFM pin PF1 signaling PWFM to reducethe pulse width on pin PWMCLK. Sub-circuit AMP3 input pin is connectedto sub-circuit PWFM pin PWMCLK. Output of AMP3 buffer pin GA2 isconnected to gate of switch Q2. Drain of Q2 is connected to anode of D70and non-saturating magnetic sub-circuit BL1 pin P2B (FIG. 18B) Turningon switch Q2 charges C4 also storing energy in magnetic element BL1.Releasing switch Q2 allows energy stored in magnetic element BL1 tocharge C4 through flyback diode D70. Larger pulse widths charge C4 tolarger voltages thus efficiently blocking part of the first stagevoltage to the final push-pull stage. This action provides regulatedvoltage to the final converter stage. The third and final push-pull(transformer) converter stage provides the galvanic isolation, filteringand typically converts the internal high voltage bus to a lowerregulated output voltage. The efficient push-pull stage producesalternating magnetizing currents in the NSME for maximum load over coremass. Constant frequency non-overlapping two-phase generator sub-circuitPPG (FIG. 43) generates the drive for the push-pull output stage. Phaseone output pin PH1 is connected to sub-circuit AMP1 pin GA1, output pinPH2 is connected to sub-circuit AMP2 pin GA1. Output of amplifier buffersub-circuit AMP1 pin GAP2 connects to gate of push-pull output switchQ6. Output of amplifier buffer sub-circuit AMP2 pin GAP2 connects togate of push-pull output switch Q9. The buffering provided by AMP1 andAMP2 shortens switch Q1 ON and OFF times greatly reducing switchinglosses. (See FIGS. 13 and 14) Regulated 18-volt power from sub-circuitCPA pin CP18+ is connected to amplifier buffer sub-circuit AMP1 pin GA+,amplifier buffer sub-circuit AMP2 pin GA+ and sub-circuit PPG pin PPG+.Drain of transistor Q6 is connected to snubber network sub-circuit SNBpin SNB1 and to non-saturating center tapped primary magnetic elementsub-circuit PPT1 pin P2H. Drain of transistor Q9 is connected to snubbernetwork sub-circuit SNA (FIG. 31) pin SNA1 and sub-circuit PPT1 pin P2L.Return node PF− connects source of transistor Q6 to snubber networksub-circuit SNB pin SNB3, transistor Q9 source, sub-circuit SNA pin SNA3and to return node GND2. Output of NSME sub-circuit PPT1 pin SH connectsto pin C7B of rectifier sub-circuit OUTA (FIG. 25), pin SL connects toC8B. Center tap of PPT1 pin SCT is the output return or negative nodeOUT− it connects to sub-circuit pin OUT− and sub-circuit IFB pin OUT−and RLOAD. Supply positive output from sub-circuit OUTA pin OUT+ isconnected to RLOAD and sub-circuit IFB pin OUT+. Elements LL1, BR, PFA,AMP, Q1, IPFFB, IFB and PFT1 provide power factor corrected AC to DCconversion and DC output regulation. The regulated high voltage outputof this converter is used to power the efficient fixed frequencypush-pull stages PPG, AMP1, AMP2, Q6, Q9, PPT1 and OUTA. Magneticelement sub-circuit PPT1 provides galvanic isolation and minimal voltageovershoot in the secondary thus minimizing filtering requirements of therectifier sub-circuit OUTA. Sub-circuit IFB provides high-speed feedbackto the AC DC converter, the speed of the boost stage provides preciseoutput voltage regulation and active ripple rejection. In the event of asudden line or load changes sub-circuit IPFFB compensates the internalboost. This system reduces losses by focusing output control in themiddle (low current) stage of the converter and by using non-saturatingmagnetics, buffered switching, and rectifying snubbers throughout eachstage. The combined improvements translate to higher systemefficiencies, higher power densities, lower operating temperatures, and,improved thermal tolerance thereby reducing or eliminating the need forforced air-cooling per unit output. The non-saturating magneticproperties are relatively insensitive to temperature (see FIG. 17), thusallowing the converter to operate over a greater temperature range. Inpractice, the operating temperature for the Kool Mu NSME is limited to200 C. by wire/core insulation; the non-saturating magnetic materialremains operable to near its Curie temperature of 500 C. Thisconfiguration provides power factor corrected input transientprotection, rapid line-load and ripple compensation, excellent outputregulation, output isolation and quiet efficient operation at hightemperatures.

FIG. 4 is a schematic diagram sub-circuit ACDCPF.

FIG. 4 is a schematic diagram of a power factor corrected single stageAC to DC converter sub-circuit ACDCPF. The invention is comprised ofline protection filter sub-circuit LL (FIG. 20) and full-wave rectifiersub-circuit BR (FIG. 22). A power factor corrected regulated boost stagewith sub-circuits PFB (FIG. 24), snubber sub-circuit SN (FIG. 30),magnetic element sub-circuit PFT1A (FIG. 18A) sub-circuit CP (FIG. 26),buffer sub-circuit AMP (FIG. 29), over temperature sub-circuit OTP (FIG.28), and voltage feedback sub-circuit FBA (FIG. 40A). Start up resistorR2, filter capacitor C1, PFC capacitor C2, flyback diode D4, switchtransistor Q1, hold up capacitors C17 and C16, and resistor R17.

FIG. 4 Table Element Value/part number C1 .01 uf C2 1.8 uf R2 100k ohmsR26 0.05 ohms Q1 IRFP 460 D4 STA1206 DI C17 100 uf C16 100 uf R17 375kohms

AC line is connected to sub-circuit LL (FIG. 20) between pins LL1 andLL2. AC/earth ground is connected to node LL0. The filtered and voltagelimited AC line appears on node/pin LL5 of sub-circuit LL1 and connectedto node BR1 of bridge rectifier sub-circuit BR (FIG. 22). The neutral/ACreturn leg of the filtered and voltage limited AC appears on pin LL6 ofsub-circuit LL is connected to input pin BR2 of BR. The line voltage isfull-wave rectified and is converted to a positive haversine appearingon node BR+ of sub-circuit BR (FIG. 22). Start up resistor R2 connectsBR+ to sub-circuit CP pin CP+. Node CP+ connects to pins PFA+ of powerfactor controller sub-circuit PFA (FIG. 24) and over temperature switchsub-circuit OTP (FIG. 28) pin GAP. Resistor R2 provides start up powerto the control element until the rectifier and regulator CP is at fulloutput. Node S1H from PFT1A is connected to node PFVC sub-circuit PFB.The zero crossing of the core bias are sensed when the voltage at S1H isat zero. The core zero crossings are used to reset the PFC and start anew cycle. The positive node of the DC side of bridge BR+ is connectedthrough capacitor C2 to BR−. C2 is selected for various line and loadconditions to de-couple switching current from the line improving powerfactor. Primary of NSME sub-circuit PFT1A (FIG. 18A) pin P1B connects topin SNL1 of snubber sub-circuit SN (FIG. 30), sub-circuit PFB pin BR+and connects to node BR+. The return line for the rectified AC power BR−is connected to the following pins; BR− of sub-circuit BR, sub-circuitPFB pin BR−, sub-circuit AMP pin GA0, sense resistor R26, capacitor[C16||C17||resistor R17], capacitor C2, sub-21 circuit CP pin CT0,sub-circuit PFT1A pin S1CT and through EMI filter capacitor C1 to earthground node LL0. Drain of output switch Q1 is connected to diode D4anode, sub-circuit PFT1A pin P1A and snubber sub-circuit SN pin SNL2.Additional rectification efficiency and protection is achieved by addingsub-circuit DSN (FIG. 30A) in parallel flyback diode D4. Sub-circuitprovides reduces the high voltage stress to Q1 until flyback diode D4begins conduction. Line coupled, power factor corrected boost regulatedoutput voltage of the AC to DC converter stage (FIG. 1) appears on nodePF+. The regulated boost output PF+ connects to the following;sub-circuit SN pin SNOUT, diode D4 cathode, capacitor [C16||C17||R17],and snubber DSN (FIG. 30A) pin SNOUT. Magnetic element winding node S1Hof sub-circuit PFT1A is connected to CP pin CT1A and pin PFVC ofsub-circuit PFB. Magnetic element winding node S1L of sub-circuit PFT1Ais connected to CP pin CT2A. Sub-circuit PFB using the phase of the ACline, and load voltage generates a command pulse PFCLK. Pin PFCLK ofsub-circuit PFB (FIG. 24) is connected to the input of buffer amplifierpin GA1 of sub-circuit AMP1 (FIG. 29). Buffered high-speed gate driveoutput pin GA2 of sub-circuit AMP is connected to gate of switch FET Q1.The buffering provided by AMP shortens switch Q1 ON and OFF timesgreatly reducing switch losses. The source of Q1 is connected to currentsense resistor R26, pin PFSC of sub-circuit PFB, connected then toreturn node BR−. The voltage developed across R26 is feedback to PFB pinPFSC. This signal is used to protect the switch in the event of an overcurrent fault. Thermal switch THS1 is connected to Q1. In the event Q1reaches approximately 105 C. THS1 opens removing power to sub-circuitAMP, safely shutting down the first stage. Normal operation resumesafter the switch temperature drops 20-30 C. closing THS1. Sub-circuitfeedback network FBA (FIG. 40A) pin PF1 is connected to sub-circuit PFBpin PF1. Converter output at node PF+ (the junction of C17||C16 and D4)is connected to sub-circuit FBA pin PF+. The return line of sub-circuitFBA pin BR− is connected to pin BR− of sub-circuit PFB. This feed backis non-isolated; network values are selected for a substantiallyconstant 385-Volt output at PF+ relative to BR−. The high-voltagehaversine from the rectifier section BR pin BR+ is connected tosub-circuit PFB pin BR+. The haversine is used with an internalmultiplier by PFB to make the converter ACDCPF appear resistive to theAC line. Sub-circuits LL1, BR, PFB, AMP, Q1, OTP, FBA, IFB and PFT1Aperform power factor corrected AC to DC conversion. The regulated highvoltage output of this converter may be used use to power one or moreexternal converters connected to the PF+ and BR− nodes. The NSMEsub-circuit PPT1A provides efficient boost action at high power levelsin a very small form factor. Sub-circuit FBA provides high-speedfeedback to the converter the speed of the boost stage provides preciseoutput voltage regulation and active ripple rejection. Thisconfiguration provides power factor corrected input transientprotection, rapid line-load response, excellent regulation, and quietefficient operation at high temperatures.

FIG. 5 is a graph comparing typical currents in saturating andnon-saturating magnetic elements. As the inductance does not radicallychange at high temperatures and currents in the NSME, the large currentspikes due to the rapid reduction of inductance common in saturatingmagnetics is not seen. As a result, destructive current levels,excessive gap leakage, magnetizing losses, and magnetic element heatingare avoided in NSME.

FIG. 6 is a schematic for non-isolated low side switch buck convertersub-circuit NILBK. Sub-circuit NILBK consists of resistor R20, diode D6,capacitor C6, FET transistor Q111, sub-circuit CP (FIG. 26), sub-circuitPFT1A (FIG. 18A), sub-circuit IFB (FIG. 40B), sub-circuit AMP (FIG. 29)and sub-circuit PWFM (FIG. 33).

FIG. 6 Table Element Value/part number R20 100k ohms R20 STA1206 DI Q111IRFP460 C6 10 uf

External power source VBAT connects to pins DCIN+ and DCIN−. From DCIN+through resistor R20 connects to sub-circuit CP pin CP+, sub-circuit AMPpin GA+ and to sub-circuit PWFM pin PWFM+. Resistor R20 provides startuppower to the converter before regulator sub-circuit CP reaches it full18-volt output. VBAT negative is connected to pin DCIN− connects tosub-circuit PWFM pin PWFM0, sub-circuit AMP pin GA0, Q111 source,sub-circuit IFB pin FBE, sub-circuit CP pin CT0, and sub-circuit PFT1pin S1CT. Magnetic element winding node S1H of sub-circuit PFT1A isconnected to CP pin CT1A. Magnetic element winding node S1CT ofsub-circuit PFT1 is connected to CP pin CT0. Magnetic element windingnode S1H of sub-circuit PFT1A is connected to CP pin CT2A. The regulated18 volts from sub-circuit CP+ is connected to R20, sub-circuit AMP pinGA+ and to sub-circuit PWFM pin PWFM+. Sub-circuit PWFM is designed forvariable pulse width operation. PWFM is configured for maximum pulsewidth 90-95% with no feedback current from sub-circuit IFB pin FBC.Increasing the feedback current reduces the pulse-width and outputvoltage from converter NILBK. Sub-circuit PWFM clock/PWM output pin CLKis connected to the input pin GA1 of buffer sub-circuit AMP. The outputof sub-circuit AMP pin GA2 is connected to the gate of Q111. Input nodeDCIN+ connects to the cathode of flyback diode D6, sub-circuit IFB pinOUT+, resistor RLOAD, capacitor C6 and pin B+. The drain of Q111 isconnected to sub-circuit PFT1 pin P1B and the anode of D6. Pin P1A ofsub-circuit PFT1A is connected to capacitor C6, RLOAD, sub-circuit IFBpin OUT− and to node B−. With sub-circuit PWFM pin CLK high buffer AMPoutput pin GA2 charges the gate of transistor switch Q111. Switch Q111conducts charging capacitor C10 through NSME PFT1A from source VBAT andstoring energy in PFT1A. Feedback output pin FBC from sub-circuit IFB isconnected to sub-circuit PWFM pulse-width adjustment pin PW1.Sub-circuit IFB removes current from PW1 commanding PWFM to reduce thepulse-width or on time of signal CLK. After sub-circuit PWFM reaches thecommanded pulse-width PWFM switches output pin CLK low turning “off”Q111 stopping the current into PFT1A. The energy not transferred intoregulator sub-circuit CP load is released from NSME PFT1A into the nowforward biased diode D6 charging capacitor C6. By modulating the “on”time of switch Q111 the converter buck voltage is regulated. Regulatedvoltage is developed across Nodes B− and B+. Sub-circuit IFB providesthe isolated feedback voltage to the sub-circuit PWFM. When sub-circuitIFB senses the converter output (nodes B+ and B−) is at the designedvoltage, current from REF is removed from PM1. Sinking current from PM1commands the PWFM to a shorter pulse-width thus reducing the converteroutput voltage. In the event the feedback signal from IFB commands thePWFM to minimum output. Gate drive to switch Q111 is removed stoppingall buck activity capacitor C6 discharges through RLOAD. Input currentfrom VBAT is sinusoidal making the converter very quiet. In addition theswitch Q111 is not exposed to large flyback voltage. Placing less stresson the switches thereby increasing the MTBF. Sub-circuit NILBK takesadvantage of the desirable properties of the NSME in this convertertopology. Adjusting the NSME 100 (FIG. 18A) primary inductance andcomponent values in sub-14 circuit IFB determines the output buckvoltage.

FIG. 8 is a schematic for a tank coupled single stage convertersub-circuit TCTP. Sub-circuit TCTP consists of resistor R20 and RLOAD,capacitor C10, Darlington transistors Q10 and Q20, sub-circuit CP (FIG.26), sub-circuit PFT1 (FIG. 18), sub-circuit OUTB (FIG. 25A),sub-circuit IFB (FIG. 40B) and sub-circuit PWFM (FIG. 33).

FIG. 8 Table Element Value/part number R20 5k ohms Q10 TST541 Q20IRFP460 C10 1.8 uf

External power source VBAT connects to pins DCIN+ and DCIN−. From DCIN+connects to Q10 collector then through resistor R20 connects tosub-circuit CP pin CP+ and to sub-circuit PWFM pin PWFM+. Resistor R20provides startup power to the converter before regulator sub-circuit CPreaches it full 18-volt output. VBAT negative is connected to pin DCIN−ground/return node GND. Node GND connects to sub-circuit PWFM0 pinPWFM0, Q20 collector, C10, sub-circuit CP pin CT0 and sub-circuit PFT1pin S1CT. Magnetic element winding node S1H of sub-circuit PFT1 isconnected to CP CT1A. Magnetic element winding node S1L of sub-circuitPFT1 is connected to CP CT2A. Magnetic element winding node S1CT ofsub-circuit PFT1 is connected to CP pin CT0. Magnetic element windingnode S2H of sub-circuit PFT1 is connected to CP pin CT2A. The regulated18 volts from sub-circuit CP+ is connected to R20 and to sub-circuitPWFM pin PWFM+. Sub-circuit PWFM is designed for a constant 50% dutycycle variable frequency generator. Sub-circuit PWFM clock output pinCLK is connected to the base of Q10 and Q20. The emitters of Q10 and Q20are connected to sub-circuit PFT1 pin P1B. This forms an emitterfollower configuration. Pin P1A of sub-circuit PFT1 is connected throughtank capacitor C10 to node GND. With PWFM CLK pin high forward biasedtransistor Q10 supplies current to the tank from BAT1 charging capacitorC10 through NSME PFT1 and transferring energy into PFT1. Sub-circuitPWFM switches CLK low turning “off” Q10 stopping the current into PFT1.Energy not transferred into the load is released from NSME PFT1 into thenow forward biased PNP transistor Q20 back into capacitor C10. Thus anyenergy not used by the secondary loads is transferred back to theprimary tank to be used next cycle. When the switching occurs at theresonant frequency large circulating currents develop in the tank. AlsoC10 is charged and discharged to very large voltages. Oscillograph inFIG. 35 is the actual voltage developed across capacitor C10 with VBATequal to 18 volts. A very large 229-Volts peak to peak was developedacross the nodes P1A and P1A of NSME PFT1. The large primary voltagegenerates large biases in the NSME PFT1 to be flux harvested by thewindings 102 and 103 (FIG. 18) and transferred to a load or rectifiersub-circuit OUTB. Magnetic element winding node S2L of sub-circuit PFT1is connected to OUTB C8b. Magnetic element winding node S2H ofsub-circuit PFT1 is connected to C7B of sub-circuit OUTB node OUT−. NodeOUT− is connected to RLOAD, pin B− and to sub-circuit IFB pin OUT−.Rectified power is delivered to pin OUT+ of OUTB and is connected toRLOAD, pin B+ and to sub-circuit IFB pin OUT+. Sub-circuit IFB providesthe isolated feedback signal to the sub-circuit PWFM. Frequency controlpin FM1 of sub-circuit PWFM is connected to sub-circuit IFB pin FBE.Internal reference pin REF of sub-circuit PWFM is connected tosub-circuit IFB pin FBC. PWFM is designed to operate at the resonatefrequency of the tank. When sub-circuit IFB senses the converter outputis at the designed voltage, current from REF is injected into FM1.Injecting current into FM1 commands PWFM to a lower frequency. Operatingbelow resonance reduces the amount of energy added to the primary tankthus reducing the converter output voltage. In the event the feedbacksignal from IFB commands the PWFM to 0 Hz all primary activity stops.Input current from VBAT is sinusoidal making the converter very quiet.In addition the switches Q10 and Q20 are never exposed to the largecirculating voltage (FIG. 35). Placing less stress on the switchesthereby increasing the MTBF. Sub-circuit TCTP takes advantage of thedesirable properties of the NSME in this converter topology. Adjustingsecondary turns allows TCTP to generate very large AC or DC outputvoltages as well as low-voltage high current outputs.

FIG. 9 is a schematic for non-isolated low side switch boost convertersub-circuit NILSBST. Sub-circuit NILSBST consists of resistor R20 andRLOAD, diode D6, capacitor C6, FET transistor Q111, sub-circuit CP (FIG.26), sub-circuit PFT1A (FIG. 18A), sub-circuit FBI (FIG. 41),sub-circuit AMP (FIG. 29) and sub-circuit PWFM (FIG. 33).

FIG. 9 Table Element Value/part number R20 100k ohms Q111 IRFP460 D6STA1206 DI C6 200 uf

External power source VBAT connects to pins DCIN+ and DCIN−. From DCIN+Resistor R20 connects to sub-circuit CP pin CP+, sub-circuit AMP pin GA+and to sub-circuit PWFM pin PWFM+. Resistor R20 provides startup powerto the converter before regulator sub-circuit CP reaches it full 18-voltoutput. VBAT negative is connected to pin DCIN− and ground return nodeGND. Node GND connects to sub-circuit PWFM pin PWFM0, sub-circuit AMPpin GA0, Q111 source, sub-circuit FBA pin BR−, sub-circuit FBA pin FBA,sub-circuit CP pin CT0, capacitor C6, resistor RLOAD, transistor Q111source, and sub-circuit PFT1 pin S1CT. Magnetic element winding node S1Hof sub-circuit PFT1A is connected to CP pin CT1A. Magnetic elementwinding node S1CT of sub-circuit PFT1 is connected to CP pin CT0.Magnetic element winding node S2H of sub-circuit PFT1A is connected toCP pin CT2A. The regulated 18 volts from sub-circuit CP+ is connected toR20, sub-circuit AMP pin GA+ and to sub-circuit PWFM pin PWFM+.Sub-circuit PWFM is designed for variable pulse width operation. PWFM isconfigured for maximum pulse width 90-95% (maximum boost voltage) withno feedback current from sub-circuit FBI. Increasing the feedbackcurrent reduces the pulse-width reducing the boost voltage and reducingthe output from converter NILSBST. Sub-circuit PWFM clock/PWM output pinCLK is connected to the input pin GA1 of buffer sub-circuit AMP. Theoutput of sub-circuit AMP pin GA2 is connected to the gate of Q111.Input node DCIN+ connects to the NSME PFT1A pin P1A. The drain of Q11 isconnected to sub-circuit PFT1A pin P1B and the anode of D6. Cathode ofdiode D6 is connected to sub-circuit FBA pin PF+, resistor RLOAD, C6 andpin BK+. With sub-circuit PWFM pin CLK high buffer AMP output pin GA2charges the gate of transistor switch Q111. Switch Q111 conducts reversebiasing diode D6 capacitor C10 stops charging through NSME PFT1A fromsource VBAT. During the time Q111 is conducting, energy is stored inNSME sub-circuit PFT1A. Feedback output pin FBC from sub-circuit FBI isconnected to sub-circuit PWFM pulse-width adjustment pin PW1.Sub-circuit FBI removes current from PW1 commanding PWFM to reduce thepulse-width or on time of signal CLK. After sub-circuit PWFM reaches thecommanded pulse-width PFFM switches CLK low turning “off” Q111 stoppingthe current into PFT1A. The energy not transferred into regulatorsub-circuit CP load is released from NSME PFT1A into the now forwardbiased diode D6 charging capacitor C6. By modulating the “on” time ofswitch Q111 the converter boost voltage is regulated. Regulated voltageis developed across Nodes B− and B+. Sub-circuit IFB provides thefeedback current to the sub-circuit PWFM. When sub-circuit IFB sensesthe converter output (nodes B+ and B−) is at or greater than thedesigned voltage, current is removed from PM1. Sinking current from PM1commands the PWFM to a shorter pulse-width thus reducing the converteroutput voltage. In the event the feedback signal from IFB commands thePWFM to minimum output. Gate drive to switch Q111 is removed stoppingall boost activity capacitor C6 charges to VBAT. Input current from VBATis sinusoidal making the converter very quiet. In addition the switchQ111 is not exposed to large flyback voltage. Placing less stress on theswitches thereby increasing the MTBF. Sub-circuit NILBK takes advantageof the desirable properties of the NSME in this converter topology.Adjusting the NSME 100 (FIG. 18A) primary inductance and componentvalues in sub-circuit IFB determines the output boost voltage.

FIG. 10 is a schematic for a two stage isolated DC to DC boostcontrolled push-pull converter BSTPP. Sub-circuit BSTPP consists ofdiode D14, capacitor C14, FET transistor Q14, sub-circuit REG (FIG. 36),sub-circuit BL1 (FIG. 18B), sub-circuit IFB (FIG. 40B), sub-circuit AMP(FIG. 29), sub-circuit DCAC1, and sub-circuit PWFM (FIG. 33). Externalpower source VBAT connects to pins DCIN+ and DCIN−.

FIG. 10 Table Element Value/part number Q31 IRFP460 D14 STA1206 DI C1410 uf

From pin DCIN+ connects to sub-circuit REG pin RIN+ and sub-circuit BL1pin P1A. Voltage regulator sub-circuit output pin +18V connects tosub-circuit AMP pin GA+ and to sub-circuit PWFM pin PWFM+. Sub-circuitREG provides regulated low voltage power to the controller and to themain switch buffers. VBAT negative is connected to pin DCIN− and groundreturn node GND. Node GND connects to sub-circuit PWFM pin PWFM0,sub-circuit AMP pin GA0, Q14 source, capacitor C14, sub-circuit IFB pinFBE, sub-circuit REG pin REG0, sub-circuit DCAC1 pin DC−. Sub-circuitPWFM (FIG. 33) is designed for variable pulse width operation. Thenominal frequency is between 20-600 Khz PWFM is configured for maximumpulse width 90% (maximum boost voltage) with no feedback current fromsub-circuit FBI. Increasing the feedback current reduces the pulse-widthreducing the boost voltage and reducing the output from converter BSTPP.Sub-circuit PWFM clock/PWM output pin CLK is connected to the input pinGA1 of buffer sub-circuit AMP (FIG. 29). The output of switch speed upbuffer sub-circuit AMP pin GA2 is connected to the gate of Q14. Inputnode DCIN+ connects to the NSME BL1 pin P1A. The drain of Q14 isconnected to sub-circuit BL1 pin P1B and the anode of D14. Cathode offlyback diode D14 is connected to sub-circuit DCAC1 pin DC+ and C14.With sub-circuit PWFM pin CLK high buffer AMP output pin GA2 charges thegate of transistor switch Q14. Switch Q14 conducts reverse biasing diodeD14 capacitor C14 stops charging through NSME BL1 from source VBAT.During the time Q14 is conducting, energy is stored in NSME sub-circuitBL1. Feedback output pin FBC from sub-circuit IFB is connected tosub-circuit PWFM pulse-width adjustment pin PW1. Sub-circuit IFB removescurrent from PW1 commanding PWFM to reduce the pulse-width or “on” timeof signal CLK. After sub-circuit PWFM reaches the commanded pulse-widthPFFM switches CLK low turning “off” Q14 stopping the current into BL1.The energy is released from NSME BL1 into the now forward biased flybackdiode D14 charging capacitor C14. By modulating the “on” time of switchQ14 the converter boost voltage is regulated. Regulated voltage isdeveloped across C14 Nodes DC+ and GND is provided to the isolatedconstant frequency push-pull DC to AC converter sub-circuit DCAC1 (FIG.2). Sub-circuit DCAC1 provides efficient conversion of the regulatedboost voltage to a higher or lower voltage set by the magneticelement-winding ratio. The center tap of the push-pull output magneticis connected to, sub-circuit OUTB pin OUT−, RLOAD, sub-circuit IFB pinOUT− and the pin OUT− forming the return line for the load and feedbacknetwork. Output of sub-circuit DCAC1 pin ACH is connected to sub-circuitOUTB pin C7 b. Output of sub-circuit DCAC1 pin ACL is connected tosub-circuit OUTB pin C8 b. Sub-circuit OUTB provides rectification ofthe AC power generated by sub-circuit DCAC1. Since the non-saturatingmagnetic converter has low output ripple, minimal filtering is requiredby OUTB. This further reduces cost and improves efficiency as losses tofilter components are minimized. Sub-circuit IFB provides the isolatedfeedback current to the sub-circuit PWFM. When sub-circuit IFB sensesthe converter output (nodes OUT+ and OUT−) is greater than thedesigned/desired voltage, current is removed from node PM1. Sinkingcurrent from PM1 commands the PWFM to a shorter pulse-width thusreducing the converter output voltage. In the event the feedback signalfrom IFB commands the PWFM to minimum output. Gate drive to switch Q14is removed stopping all boost activity capacitor C14 charges to VBAT. Asthe non-saturating does not saturate the destructive noisy current“spikes” common to prior art are absent. Input current from VBAT tocharge C14 is sinusoidal making the converter very quiet. In additionthe switch Q14 is not exposed a potentially destructive current spike.Placing less stress on the switches thereby increasing the MTBF.Sub-circuit BSTPP takes advantage of the desirable properties of theNSME. Adjusting the NSME BL1 (FIG. 18B) sets the amount of boost voltageavailable to the final push-pull isolation stage. Greater efficienciesare achieved at higher voltages. The final output voltage is set by thefeedback set point and the turns ratio of the push-pull element PPT1(FIG. 19).

FIG. 11 is a graph of permeability as a function of temperature fortypical prior art magnetic element material. The high permeabilitymaterial in FIG. 11 exhibits large changes in permeability of almost100% over a 100 C. range as compared to the less than 5% change for thematerial in FIG. 17. The increase in permeability at high temperaturesof the prior art material increases the flux density resulting in coresaturation for a constant power level. (See FIG. 12) Thus the prior artcore must be derated at least 100% to operate over extendedtemperatures. The instant invention takes advantage of the desirableproperties of the NSME. Eliminating the need to derate the magneticelement. As the magnetic element performs better at high temperatures,currently limited by melting wire insulation.

FIG. 12 is a graph of flux density as a function of temperature fortypical prior art magnetic element material. The reduction of maximumflux density with temperature is typical of the saturating magneticelement prior art material. Thus the prior art core is commonly deratedat least 100% to operate over extended temperatures. Resulting in alarger more expensive design, and or the requirement to cool the core.

FIG. 12A is a graph of magnetic element losses for various fluxdensities and operating frequencies typical of prior art magneticelement material.

FIG. 13 is a graph showing standard switching losses. The hashed arearepresents the time when the switch is in a resistive state. The hashedarea is proportional to the amount of energy lost each time the outputswitch operates. Total power lost is the product of the loss per switchtimes the switching frequency.

FIG. 14 is a graph showing the inventions switching losses. The hashedarea represents the time when the switch is in a resistive state. Thesmaller hashed area is due to the action of the buffer in FIG. 29 andthe snubber isolation diode D805 in FIG. 30. Generally the NSME has awider usable frequency band and can be magnetized from higher primaryvoltages. Higher operating voltages have proportionally smaller currentsfor a given power level thus proportionally lower losses. Switchinglosses more closely resemble I²R losses. Most switching loss occursduring turn “on” and turn “off” transitions; total switching losses arereduced proportionally by the lower switching frequencies and fastertransition times characteristic of the disclosed NSME converters. Inaddition the properties of the NSME allow operation at temperatureextremes beyond the tolerance of standard prior art magnetics and theirgeometry's. The combined contributions of the above yields a converterthat requires little or no forced air-cooling. (See FIGS. 15, 16, and17)

FIG. 15 is a graph of the NSME magnetization curves for Kool Mumaterial. The invention makes advantageous use of the availablesaturation range of the NSME.

FIG. 16 is a graph of the Kool Mu NSME losses for various flux densitiesand operating frequencies. It can be seen from the data that much higherflux densities are available per unit losses over the prior art.

FIG. 17 is a plot of permeability vs. temperature for several Kool Mumaterials. This data demonstrates the usefulness and stability of themagnetic properties over temperature.

FIG. 18 is a schematic representation of the non-saturating magneticboost element PFT1. Sub-circuit PFT1 consists of a primary winding 100around a NSME 101 with two center-tapped windings 102 and 103.

FIG. 18 Table Element Value/part number 100 55 turns 203 uh 101 2 x77932-A7 102 14 turns 102 14 turns

The primary winding 100 has nodes P1B and P1A for connections toexternal AC source. Secondary 102 winding has center-tapped node S1CTand node S1H and S1L connections to the upper and lower halvesrespectively. Secondary 103 winding has center-tapped node S2CT and nodeS2H and S2L connections to the upper and lower halves respectively. Both102 and 103 are connected to external full-wave rectifier assemblies.Magnetic element magnetic element 101 comprises a non-saturating, lowpermeability magnetic material. The permeability is on the order of 26 uwith a range of 1 u to 550 u, as compared to the prior art, which rangesfrom 1500 to 5000 u. Flyback management is of concern when using NSME ina boost converter because the magnetic element generates high drainsource voltages across the primary switch during the reverse recoverytime of the flyback (output) diode. The magnitude per cycle of flybackcurrent from NSME is greater for a given input magnetizing forcerelative to the prior art. (See FIG. 5) For example, Kool Mu torroids(Materials from Magnetics) are suitable for this application. Thismaterial is not identified by way of limitation. The material comprises,by weight, 85% iron, 6% aluminum, and 9% silicon. Further, the magneticelement may be air, (permeablity=1); a molypermalloy powder, (MPP) ahigh flux MPP, a powder, a gapped ferrite, a tape wound, a cut magneticelement, a laminated, or an amorphous magnetic element. Unlike the priorart, the NSME is temperature tolerant in that the critical parameters ofpermeability and saturability remain substantially unaffected duringextreme thermal operation over time. Some materials such as air alsoexhibit little or no change in permeability or saturation levels overtime, temperature, and conditions. The prior art uses high permeabilitysaturable materials often greater than 2000u permeability. Thesemagnetics exhibit undesirable changes in permeability and saturationduring operation at or near rated output making operation at high powerlevels and temperature difficult. See the permeability vs. temperatureFIG. 11. This deficiency is overcome by the use of expensive oversizedmagnetic elements or output current sharing with multiple supplies. (Seethe graph b_(sat) vs. temperature FIG. 12) This invention takesadvantage of the desirable properties of NSME. See the permeability vs.temperature FIG. 17. Prior art saturating magnetic element commonly isoperating at frequencies greater than 500 KHz to achieve greater powerlevels. As a result practitioners experience exponentially greater corelosses (see FIG. 12A) at high frequencies. NSME support operation atlower frequencies 20-600 KHz further reducing switching losses andmagnetic element losses allowing operation at even higher temperatures.See the loss density vs. flux density FIG. 16. Unlike the prior art, theinstant invention uses voltage mode control with over-current shutdown.Material selection is also based upon mass and efficiency. By increasingthe mass of the magnetic element, more energy is coupled moreefficiently. Since there are reduced losses, the dissipation profilefollows I2R/copper losses. The magnetic element is operated at dutycycles of 0%+ to 90%, which, when used to control the primary sidepush-pull voltage, results in efficiencies on the order of 90%.

FIG. 18A is a schematic representation of the NSME PFT1A Sub-circuittransformer PFT1A consists of a primary winding 100 around a NSME 101with a center-tapped winding 102.

FIG. 18A Table Element Value/part number 100 55 turns 230 uh 101 2 x77932-A7 102 14 turns

The primary winding 100 has nodes P1B and P1A for connections toexternal AC source. Secondary 102 winding has center-tapped node S1CTand node S1H and S1L connections to the upper and lower halvesrespectively. Winding 102 are typically connected to external full-waverectifier assemblies. Magnetic element 101 comprises a non-saturating,low permeability magnetic material. The permeability is on the order of26u with a range of 1 u to 550u, as compared to the prior art, which ison the order of 2500u.

Flyback management is of concern when using such a magnetic elementbecause the magnetic element generates high drain source voltages acrossthe primary switch during the reverse recovery time of the flybackdiode. Flyback current is available for longer periods after the primaryswitch opens. (See FIG. 5) For example, Kool Mu (Materials fromMagnetics are suitable for this application. This material is notidentified by way of limitation. The material comprises, by weight: 85%iron, 6% aluminum, and 9% silicon. Further, the magnetic element may beair; (air magnetic element permeablity=1); a molypermalloy powder (MPP)magnetic element; a high flux MPP magnetic element; a powder magneticelement; a gapped ferrite magnetic element; a tape wound magneticelement; a cut magnetic element; a laminated magnetic element; or anamorphous magnetic element. During operation the temperature of the NSMErises, the permeability slowly decreases, thereby increasing thesaturation point. Some materials such as air exhibit no or very smallchanges in permeability or saturation levels. Unlike prior art usinghigh permeability materials greater than 2000u permeability rapidlyincreases at high temperatures. See the permeability vs. temperatureFIG. 11. Prior art also suffers from reduced magnetic element saturationlevels at high temperatures, making operation at high power levels andtemperature difficult and may require the use of expensive oversizedmagnetic elements. See the graph b_(sat) vs. temperature FIG. 12 thisinvention takes advantage of the desirable NSME properties. See thepermeability vs. temperature FIG. 17. Operation at lower frequencies20-600 KHz reduces switching losses and magnetic element losses allowingoperation at higher temperatures. See the loss density vs. flux densityFIG. 16. Unlike the prior art, the instant invention uses voltage modecontrol with over-current shutdown. Material selection is also basedupon mass and efficiency. By increasing the mass of the magneticelement, more energy is coupled more efficiently. Since there arereduced losses, the dissipation profile follows I2R/copper losses. Themagnetic element is operated at duty cycles of 0%+ to 90%, which, whenused to control the primary side push-pull voltage, results inefficiencies on the order of 90%.

FIG. 18B is a schematic representation of the NSME BL1 Sub-circuit BL1consists of a winding 100 around a NSME 101.

FIG. 18 Table Element Value/part number 107 40 turns 50 uh 101 2 x77932-A7

Magnetic element BL1 may also be constructed from one or more magneticelements in series or parallel. Assuming minimal mutual coupling thetotal inductance is the arithmetic sum of the individual inductances.For elements in parallel the (assuming minimal mutual coupling) thetotal inductance is the reciprocal of the arithmetical sum of thereciprocal of the individual inductances. In this way multiple magneticelements may be arranged to meet packaging, manufacturing, and powerrequirements. The primary winding 100 has nodes P2B and P2A forconnections to external AC source. Magnetic element 101 comprises anon-saturating, low permeability magnetic material. The permeability ison the order of 26 u with a range of 1 u to 550 u, as compared to theprior art, which is on the order of 2500 to 5000 u. Flyback managementis of concern when using such a magnetic element because the magneticelement generates high drain source voltages across the primary switchduring the reverse recovery time of the flyback diode. Flyback currentis available for longer periods after the primary switch opens. (SeeFIG. 5) For example, Kool Mu (Materials from Magnetics are suitable forthis application. This material is not identified by way of limitation.The material comprises, by weight: 85% iron, 6% aluminum, and 9%silicon. Further, the magnetic element may be air (air magnetic elementpermeablity=1); a molypermalloy powder (MPP) magnetic element; a highflux MPP magnetic element; a powder magnetic element; a gapped ferritemagnetic element; a tape wound magnetic element; a cut magnetic element;a laminated magnetic element; or an amorphous magnetic element. Duringoperation temperature of the magnetic element rises, the permeabilityslowly decreases, thereby increasing the saturation point. Somematerials such as air exhibit no or very small changes in permeabilityor saturation levels. Unlike prior art using high permeability materialsgreater than 2000 u permeability rapidly increases at high temperatures.See the permeability vs. temperature FIG. 11. Prior art also suffersfrom reduced magnetic element saturation levels at high temperatures,making operation at high power levels and temperature difficult and mayrequire the use of expensive oversized magnetic elements. (See the graphb_(sat) vs. temperature FIG. 12) This invention takes advantage of thedesirable NSME properties. (See the permeability vs. temperature FIG.17.) Prior art often operates at high switching frequencies 100-1000 kHzto avoid the saturation problem. Only to increase switching and corelosses. (See FIG. 12A) This inventions use of the desirable NSMEproperties allows operation at lower frequencies 20-600 KHz furtherreducing switching losses and magnetic element. See the loss density vs.flux density FIG. 16. Unlike the prior art, the instant invention usesvoltage mode control with over-current shutdown. Material selection isalso based upon mass and efficiency. By increasing the mass of themagnetic element, more energy is coupled more efficiently. Since thereare reduced losses, the dissipation profile follows I2R/copper losses.

FIG. 18C is a schematic representation of a distributed NSME PFT1D. Thisis shown to exemplify distributed magnetics enable advantageous highvoltage converter design variations that support form factor flexibilityand multiple parallel secondary outputs from series coupled voltagedivided primary windings across multiple NSME. This magnetic strategy isuseful in addressing wire insulation, form factor and packaginglimitations, circuit complexity and manufacturability. In this example a500 W converter is required to fit in a low profile package. Sub-circuitPFTD1 consists of three magnetic elements 120, 121 and 124 with seriesconnected primaries.

FIG. 18C Table Element Value/part number 113 77352-A7 122 23 Turns 12323 Turns 112 67 uh (55 turns) 114 77352-A7 116 67 uh (55 turns) 11777352-A7 118 67 uh (55 turns)

AC voltage is applied to 112 pin P1B then from P1C through conductor 115to 116 pin P1A. Winding 116 pin P1E is connected through conductor 119to 118 pins P1F then to pin P1A. Original Sub-circuit PFT1 (FIG. 18)consists of a primary winding 100 around a NSME 101 with twocenter-tapped windings 122 and 123. By way of example sub-circuit PFT1Dwill be implemented as three magnetic elements. For a 500-wattexpression a total inductance of 203 uH is required in winding 100 (FIG.18). Dividing the primary inductance by the number of elements, in thiscase three requires elements 112, 116 and 118 have 67 uH of inductance.The energy storage is equally distributed over the magnetic assembly120, 121 and 124. The 500 watt converter in (FIG. 1) employs two (KoolMu part number 77932-A7) 0.9 oz (25 gram) NSME to form 101 (FIG. 18).Sub-circuit PFT1 magnetic element 101 (FIG. 18) may be expressed asthree 0.5-0.7 oz (14-19 gram) elements. Three 0.5-oz Kool Mu elements(part number 77352-A7) were selected. To realize 67 uH of primaryinductance 55 turns are required for elements 112, 116 and 118. Theprimary circuit has nodes P1B and P1A for connections to external ACsource. Secondary 102 winding has center-tapped node S1CT and node S1Hand S1L connections to the upper and lower halves respectively.Secondary 123 winding has center-tapped node S2CT and node S2H and S2Lconnections to the upper and lower halves respectively. Both 122 and 123are connected to external full-wave rectifier assemblies. Magneticelement magnetic element 120, 121 and 124 comprises a non-saturating,low permeability magnetic material. The permeability is on the order of26 u with a range of 1 u to 550 u, as compared to the prior art, whichis on the order of 2500 u. Flyback management is of concern when usingsuch a magnetic element because the magnetic element generates highdrain source voltages across the primary switch during the reverserecovery time of the flyback diode. Flyback current is available forlonger periods after the primary switch opens. (See FIG. 5) For example,Kool Mu (Materials from Magnetics are suitable for this application.This material is not identified by way of limitation. The materialcomprises, by weight: 85% iron, 6% aluminum, and 9% silicon. Further,the magnetic element may be air (air magnetic element permeablity=1); amolypermalloy powder (MPP) magnetic element; a high flux MPP magneticelement; a powder magnetic element; a gapped ferrite magnetic element; atape wound magnetic element; a cut magnetic element; a laminatedmagnetic element; or an amorphous magnetic element. During operation thetemperature of the NSME, the permeability slowly decreases, therebyincreasing the saturation point. Some materials such as air exhibit noor very small changes in permeability or saturation levels. Unlike priorart using high permeability materials greater than 2000 u permeabilityrapidly increases at high temperatures. See the permeability vs.temperature FIG. 11. Prior art also suffers from reduced magneticelement saturation levels at high temperatures, making operation at highpower levels and temperature difficult and may require the use ofexpensive oversized magnetic elements. (See the graph b_(sat) vs.temperature FIG. 12) This invention takes advantage of the desirableNSME properties. See the permeability vs. temperature FIG. 17. Prior artsaturating magnetic element commonly is operating at frequencies greaterthan 500 KHz to achieve greater power levels. As a result practitionersexperience exponentially greater core losses (see FIG. 12A) at highfrequencies. NSME allows operation at lower frequencies 20-600 KHzfurther reduces switching losses and magnetic element losses allowingoperation at even higher temperatures. (See the loss density vs. fluxdensity FIG. 16) Unlike the prior art, the instant invention usesvoltage mode control with over-current shutdown. Material selection isalso based upon mass and efficiency. By increasing the mass of themagnetic element, more energy is coupled more efficiently. Since thereare reduced losses, the dissipation profile follows I2R/copper losses.The magnetic element is operated at duty cycles of 0%+ to 90%, which,when used to control the primary side push-pull voltage, results inefficiencies on the order of 90%. FIG. 19 is a schematic representationof the non-saturating push-pull magnetic element sub-circuit PPT1Sub-circuit PPT1 consists of a center-tapped primary winding 104 arounda NSME 106 with one secondary center-tapped winding 105.

FIG. 19 Table Element Value/part number 106 77259-A7 105 10 Turns 104 70Turns

The primary winding 104 has nodes P2H and P2L for connections toexternal AC sources, and common center-tap node P2CT. Secondary 105winding has center-tapped node SCT and nodes SH and SL connections tothe upper and lower halves respectively. The invention is not limited toa single output. More secondary windings may be added for additionaloutputs. Secondary 105 is connected to an external full-wave rectifierassembly (Example FIGS. 25 or 26). The magnetic element magnetic element106 comprises a non-saturating, low permeability magnetic material. Thepermeability is on the order of 26 u with a range of 1 u to 550 u, ascompared to the prior art, which is on the order of 2500 u. Flybackmanagement is of concern when using such a magnetic element as highdrain source voltages across the primary switch are generated during thereverse recovery of the flyback diode. The falling flyback current isavailable for a longer period. (See FIG. 5) For example, Kool Mu(magnetic elements from Magnetics are suitable for this application.This material is not identified by way of limitation. The materialcomprises, by weight; 85% iron, 6% aluminum, and 9% silicon. Further,the magnetic element may be air (comprise an air magnetic element); amolypermalloy powder (MPP) magnetic element; a high flux MPP magneticelement; a powder magnetic element; a gapped ferrite magnetic element; atape wound magnetic element; a cut magnetic element; a laminatedmagnetic element; or an amorphous magnetic element. During operation thetemperature of the NSME rises, the permeability slowly decreases,thereby increasing the saturation point. Unlike prior art using highpermeability materials greater than 2000 u permeability rapidlyincreases at high temperatures. See the permeability vs. temperatureFIG. 11. Prior art also suffers from reduced magnetic element saturationlevels at high temperatures, making operation at high power levels andtemperature difficult and may require the use of expensive oversizedmagnetic elements. (See the b_(sat) vs. temperature FIG. 12) Thisinvention takes advantage of the desirable NSME properties. (See thepermeability vs. temperature FIG. 17) Operation at lower frequencies20-600 KHz reduces switching losses and magnetic element losses allowingoperation at higher temperatures. See the loss density vs. flux densityFIG. 16. Unlike the prior art, the instant invention uses voltage modecontrol with over-current shutdown. Material selection is also basedupon mass and efficiency. By increasing the mass of the magneticelement, more energy is coupled more efficiently. Since there arereduced losses, the dissipation profile follows I2R/copper losses. Themagnetic element primary is driven in a push-pull fashion at a dutycycle of 48-49% resulting in efficient use of the magnetic elementvolume.

FIG. 19A is a schematic representation of the non-saturating push-pullmagnetic element sub-circuit PPT1. Sub-circuit PPT1 consists of acenter-tapped primary winding 134 around a NSME 136 with one secondarycenter-tapped winding 135.

FIG. 19A Table Element Value/part number 136 77259-A7 135 10 Turns 13470 Turns

The primary winding 134 has nodes P2H and P2L for connections toexternal AC sources, and common center-tap node P2CT. Secondary 135winding has center-tapped node SCT and nodes SH and SL connections tothe upper and lower halves respectively. The invention is not limited toa single output winding. More secondary windings may be added foradditional outputs. Secondary 135 is connected to an external full-waverectifier assembly such as OUTA (FIG. 25), OUTB (FIG. 25A) and OUTBB(FIG. 25B). The magnetic element 136 comprises a non-saturating, lowpermeability magnetic material. The permeability is on the order of 26 uwith a range of 1 u to 550 u, as compared to the prior art, which is onthe order of 2500 u. Flyback management is of concern when using such amagnetic element as high drain source voltages across the primary switchare generated during the reverse recovery of the flyback diode. Thefalling flyback current is available for a longer period. (See FIG. 5)For example, Kool Mu (magnetic elements from Magnetics are suitable forthis application. This material is not identified by way of limitation.The material comprises, by weight; 85% iron, 6% aluminum, and 9%silicon. Further, the magnetic element may be air (comprise an airmagnetic element); a molypermalloy powder (MPP) magnetic element; a highflux MPP magnetic element; a powder magnetic element; a gapped ferritemagnetic element; a tape wound magnetic element; a cut magnetic element;a laminated magnetic element; or an amorphous magnetic element. Duringoperation the temperature of the NSME rises, the permeability slowlydecreases, thereby increasing the saturation point. Unlike prior artusing high permeability materials greater than 2000 u permeabilityrapidly increases at high temperatures. See the permeability vs.temperature FIG. 11. Prior art also suffers from reduced magneticelement saturation levels at high temperatures, making operation at highpower levels and temperature difficult and may require the use ofexpensive oversized magnetic elements. (See the b_(sat) vs. temperatureFIG. 12) This invention takes advantage of the desirable NSMEproperties. (See the permeability vs. temperature FIG. 17) Operation atlower frequencies 20-600 KHz reduces switching losses and magneticelement losses allowing operation at higher temperatures. See the lossdensity vs. flux density FIG. 16. Unlike the prior art, the instantinvention uses voltage mode control with over-current shutdown. Materialselection is also based upon mass and efficiency. By increasing the massof the magnetic element, more energy is coupled more efficiently. Sincethere are reduced losses, the dissipation profile follows I2R/copperlosses. The magnetic element primary is driven in a push-pull fashion ata duty cycle of 48-49% resulting in efficient use of the magneticelement volume.

FIG. 20 lightning input protection and filter sub-circuit LL

FIG. 20 is a schematic showing the inventions filter and lightning inputprotection circuit for an AC line connected converter. The protectionsub-circuit LL comprises a Spark gap A1, diodes D20 and D21, capacitorC1 and magnetic elements L1 and L2.

FIG. 20 Table Element Value/part number L1 375 uH L2 375 uH C61 0.01 uFC60 0.01 uF A1 400 V Spark Gap C1 0.1 uF D20 1000 V/25A D21 1000 V/25AD22 1000 V/25A D23 1000 V/25A C2 1.8 uf

The AC line is connected to node LL2. The common input frequencies of DCto 440 Hz may be extended beyond this range with component selection.Node LL2 is connected to NSME L1 then to node LL5, the spark gap A1,anode of diode D22 and the cathode of diode D20. Filter capacitor C60 isconnected between node LL0 and LL6. Filter capacitor C61 is connectedbetween node LL0 and LL5. The low side of AC line is connected to nodeLL1 then to magnetic element L2 the other side L2 is connected to sparkgap A1, anode of diode D23 and the cathode of diode D21 and to node LL6.Capacitor C1 is connected to earth ground C1 attenuates noise generatedby the converter. The use of non-saturating magnetic allows the inputmagnetic elements to absorb very large voltages and currents commonlygenerated by lightning, often without causing spark gap A1 to clamp.During UL testing sixty 16 ms 2000V pulses were applied between LL1 andLL2 without realizing spark gap A1 was missing with out damage. Duringnormal operation the NSME L1 flux density is a few hundred gauss. The 75u material from the graph of Flux Density v. Magnetizing Force (FIG. 15)will accept flux densities at least 50 times greater with outlimitation. This is an example of the magnetic elements ability toperform well at flux densities many times greater than prior art.Elements L1 and L2 will block differential or common mode linetransients. In the event of a very large or long duration line toneutral transient, spark gap A1 will clamp the voltage to a safe levelof about 400V. The NSME L1 and L2 have the added benefit of reducingconducted noise generated by the converter.

FIG. 21 alternate lightning input protection sub-circuit LLA

FIG. 21 is a schematic showing the inventions alternate lightningprotection sub-circuit for an AC line connected converter. Theprotection circuit comprises a fuse F1, Spark gap A1, capacitors C1, C60and C61 and NSME L3.

FIG. 21 Table Element Value/part number L3 750 uH C61 0.01 uF C60 0.01uF F1 10A A1 400 V Spark Gap C1 0.1 uF D20 1000 V/25A D21 1000 V/25A D221000 V/25A D23 1000 V/25A C2 1.8 uf

High side of AC line is connected to node LL2, fuse F1 the load side ofthe fuse is connected to NSME L3 and to capacitor C61. The load side L3is connected to spark gap A1 and the cathode of diode D20 and anode ofD22 forming node LL5. The low side of AC line is connected to node LL6,capacitor C60, spark gap A1, and the cathode of diode D21 and anode ofD23. The anodes of diodes D20 and D21 are connected to Capacitor C1.Capacitor C1 is connected to earth ground. C1 attenuates radiated noiseor EMI generated by the converter. The cathode of diodes D22 and D23 areconnected to Capacitor C2. Capacitor C2 decouples high frequencyharmonic currents from the line. Capacitors C1, C61 and C60 areconnected to earth ground node LL0. The use of non-saturating magneticsallows the input magnetic element to absorb very large voltages andcurrents commonly generated on the AC line by lightning. A transient onthe AC line will be limited by capacitors C60 and C61 and blocked by thenon-saturating magnetic L3. In the event of a very large or longduration line to neutral transient, magnetic element L3 will allow thevoltage to rise across spark gap A1, the spark gap will clamp thevoltage to a safe level protecting the rectifier diodes D20-D23. TheNSME L3 has the added benefit of reducing conducted noise generated bythe converter. C1 connected to the ground plane is effective inattenuating conducted and radiated EMI.

FIG. 22 AC line rectifier sub-circuit BR

FIG. 22 is a schematic showing the inventions AC line rectifier. Therectifier sub-circuit BR1 comprises diodes D20, D21, D22 and D23 andcapacitor C2.

FIG. 22 Table Element Value/part number D20 1000 V/25A D21 1000 V/25AD22 1000 V/25A D23 1000 V/25A C2 1.8 uf

An AC or DC signal from the input filter is connected to bridgerectifier to nodes BR1 and BR2. Node BR1 connects diode D22 anode to D20cathode. Node BR2 connects diode D23 anode to D21 cathode. Node BR+connects diode D22 cathode to D23 cathode. Node BR− connects diode D20anode to D21 anode. The common input frequencies of DC to 440 Hz may beextended beyond this range with component selection. Capacitor C2 isselected to improve power factor for a particular operating frequencyand to de-couple switching currents from the line. Diodes are selectedto reliably block the expected line voltage and current demands of thenext converter stage.

FIG. 23 controller sub-circuit PFA

FIG. 23 is the inventions AC to DC controller sub-circuit. Sub-circuitPFA consists of resistors R313 and R316, capacitors C308, and C313 andPWM controller IC U1A.

FIG. 23 Table Element Value/part number C311 0.1 uf C308 .01 uf R313 15kohms R316 15k ohms C313 4700 pf R308 25k ohms U1A MIC38C43 (Micrel)

Control element U1A connects to a circuit with the following seriesconnections: from pin 1 to feedback node/pin PF1 then to capacitor C308then to the pin 2 node of U1A. Internal 5.1-volt reference U1A pin 8 ornode PFA2 through resistor R308 to the pin 4 node. U1A pin 4 isconnected through capacitor C313 to return node BR−. This arrangementallows the PFC output to be pulse width modulated with application ofvoltage to PF1. External feedback current applied to U1A pin 1 and nodePF1. Node PFVC is connected to resistor R313 to pin 3 of U1A. ResistorR316 is connected to pin 3 then to return node BR−. Power pin 7 isconnected to node PFA+. Control element switch drive U1A pin 6 isconnected to node PFCLK. Return ground node of U1A pin 5 is connected toreturn node BR−. In the event of a component failure in the primary feednetworks such as IPFFB (FIG. 40), FBA (FIG. 40A), IFB (FIG. 40B) and FBI(FIG. 41). The output voltage of the boost stage may rapidly increase todestructive levels. Fast over voltage feedback networks IOVFB (FIG. 40C)or OVP2 (FIG. 42B) increases the current into PF1 thereby limiting theoutput voltage to a safe level. In addition latching type over voltageprotection networks such as OVP (FIG. 42), OVP1 (FIG. 42A) and OVP2(FIG. 42B) maybe used. The latching type kills power to the controlcircuit thereby stopping the boost action. The latching type networksrequire power to be cycled to the converter to reset the latch. IFBInput node PFVC is connected to resistor R313 to internal zero crossingdetector connected to pin 3 and through R316 to return node BR−. PFVC isconnected to a magnetic element winding referenced to BR−. A newconduction cycle is started each time the bias in the magnetic elementgoes to zero. Power factor corrected is realized by chopping the inputat a high frequency. The average pulse width decreases at higher linevoltage and increases at lower voltage for a given load. Frequency islower at line peaks and higher around zero crossings. In this way theconverter operates with a high input power factor.

FIG. 24 Controller with power factor corrected sub-circuit PFB FIG. 24is the alternate power factor controller sub-circuit. Sub-circuit PFBconsists of resistors R313, R339, R314, R315, R328, R340, R341 and R346,diode D308, capacitors C310, C318, C338, C340, C341 and C342, transistorQ305, and control element IC U1B.

FIG. 24 Table Element Value/part number Q305 BCX70KCT R339 432k ohmsC338 0.22 uf C318 0.22 uf R314 2.2 MEG ohms R315 715k ohms C341 0.33 ufC342 0.01 uf C340 0.001 uf R328 1 MEG ohms R346 7.15k ohms D308 10BQ040R340 449k ohms R313 22k ohms U1B MC34262 (Motorola) R341 499k ohms

Control element U1B connects to a circuit with the following seriesconnections: from pin 1 to node/pin PF1 to capacitor C338 in series withresistor R339, and then to the pin 2 node of U1B. Pin 1 is the input toan internal error amplifier and connection to external feedbacknetworks. (See FIGS. 40, 40A, 40B, 40C and 41) Increasing the voltage onpin 1 decreases the pulse width of the PFCLK node pin 7. Resistor R328is connected to the fullwave rectified AC line haversine voltage on nodeBR+ then to U1B pin 3 and then to resistor R346 in parallel withcapacitor C342 to return node BR−. Node PFSC connects to seriesresistors [R341+R340] which are connected to U1B pin 4 then to diodeD308 in parallel with capacitor C340 to return node BR−. Power to PFCcontroller is applied to node PFB+ and to U1B pin 8. Output clock nodePFCLK is connected to U1B pin 7, to external buffer sub-circuit AMP(FIG. 29). Transistor Q305 collector is connected to the pin 2 node ofU1B. The base is connected in series through resistor R314 to capacitorC318, then to the pin 2 node of U1B. The base is also connected to[C310||R315], then to return node BR−. Emitter of Q305 is connected toreturn node BR−. Transistor Q305 provides a soft start compensation rampto the controller error amp reducing the stress and DC overshoot in theconverter at power up. Capacitor C341 is connected from U1 pin 2 toreturn node BR−. U1B pin 1 is connected to pin PF1, capacitor C338 inseries with resistor R339 to transistor Q305 collector and to U1 pin 2.Current switched by PFC power switch Q1 (FIGS. 4 & 3) is sensed by R26(see FIG. 4). Series resistors [R340+R341] to U1B pin 4 connect voltagedeveloped across R26. This voltage is compared to an internal 1.5-voltreference, comparator output turns off the switch drive pin 7 of U1Bduring times of high current that occur during startup or during veryhigh load or low line conditions. Capacitor C340 is connected between U1pin 4 to return node BR− filter high frequency components. Schottkydiode D308 connected between U1 pin 4 to return node BR− protects thecontroller (U1 pin 4) substrate from negative current injection. Maximumswitch current value is set by R26 over currents are automaticallylimited in each cycle by the PFC controller. The rectified fullwavehaversine at pin 3 of U1B is multiplied by the error voltage on pin 2.The product is compared to the magnetic element/switch current measuredby R26 on pin 4. Gate drive on pin 7 turns off when the sensed magneticelement current increases to the current comparator level. This actionhas the effect of modulating the switch Q1 “on” time tracking the ACline voltage. External feedback networks are connected to node PF1. Inthe event of a component failure in the primary feed network such asIPFFB (FIG. 40), FBA (FIG. 40A), IFB (FIG. 40B) and FB1 (FIG. 41). Theoutput voltage of the boost stage may rapidly increase to destructivelevels. Fast over voltage feedback networks IOVFB (FIG. 40C) or OVP2(FIG. 42B) increases the current into PF1 thereby limiting the outputvoltage to a safe level. In addition latching type over voltageprotection networks such as OVP (FIG. 42), OVP1 (FIG. 42A) and OVP2(FIG. 42B) maybe used. The latching type removes power to the controlcircuit thereby stopping the boost action. The latching type networksrequire power to be cycled to the converter to reset the latch.Modulating the voltage at PF1 changes the duty cycle of the PFC and thefinal output voltage. In this way the PFC may be used as a pre-regulatorto additional output stages.

FIG. 25 Output rectifier and filter sub-circuit OUTA

FIG. 25 is a schematic of a full wave rectified output stage and filtersub-circuit OUTA. The rectifier stage consists of diodes D80 and D90.The filter consists of resistor R21, magnetic element L30 and capacitorsC26, C27, C28, C29, C30, C31 and C32.

FIG. 25 Table Element Value/part number D80 40CTQ150 D90 40CTQ150 R21100 ohms C26 500 pf C27 200 pf C28 0.1 uf C29 10,000 uf C30 10,000 ufC31 0.1 uf C32 200 pf L30 10 uh

Input node/pin C7B is connected to the high side of externalcenter-tapped magnetic element secondary winding. Node C7B connects toanode of diode D8 and to capacitors C26 and C27 in the followingarrangement. Capacitor C27 is connected across diode D80, capacitor C26is connected in series to R21. Input node/pin C8B is connected to thelow side of external center-tapped magnetic element secondary winding.Pin C8B is connected to anode of diode D9 and to resistor R21, capacitorC32 is connected across diode D90. Capacitors C27 and C32 is a smallvalue to reduce high frequency noise generated by rapid switching thehigh speed rectifier D80 and D90 respectively. Capacitor C26 andresistor R21 are used to further dissipate high frequency energy. Anodeof diodes D80 and D90 is connected to parallel capacitors C28||C29 andNSME L30. Capacitors C28 and C31 are solid dielectric types selected forlow impedance to high frequency signals. Capacitors C29 and C30 arelarger polarized types selected for low impedance at low frequencies andfor energy storage. Magnetic element L3 is connected to diode D8 cathodethe second terminal of L30 is connected to parallel capacitors C31 andC30 and pin OUT+. Node OUT+ is the output positive and is connected toexternal feedback sense line to isolated feedback network. The otherside of parallel capacitors [C28||C29||C30||C31] is connected to pinOUT− and the center-tap of the magnetic element secondary forming thereturn node. The combination of capacitors [C28||C29], L30 andcapacitors [C30||C31] form a low pass pi type filter. Sub-circuit OUTAperforms efficient fullwave rectification and filtering.

FIG. 25A Output rectifier sub-circuit OUTB

FIG. 25A is a schematic of a full wave rectified output stage. Therectifier stage consists of diodes D80 and D90 and capacitors C931 andC928.

FIG. 25A Table Element Value/part number D80 40CTQ150 D90 40CTQ150 C928.01 uf C931 10,000 uf

Input node/pin C7B is connected to high side of external center-tappedmagnetic element secondary winding. Node C7B connects to anode of diodeD80. Input node/pin C8B is connected to low side of externalcenter-tapped magnetic element secondary winding is connected to anodeof diode D90. Node OUT− is the negative output and return line to theexternal isolated feedback network and load not shown. Cathodes ofdiodes D80 and D90 are connected to parallel capacitors C931 and C928.Capacitor C928 is a solid dielectric type selected for low impedance tohigh frequency signals. Capacitor C931 is a larger polarized selectedfor low impedance to low frequency signals and for energy storage. NodeOUT+ is the output positive and is connected to external feedback senseline to isolated feedback network. The other side of parallel capacitorsC928||C931 is connected to the center-tap of the magnetic elementsecondary forming the node OUT−. The use of the NSME for the push-pullmagnetic element requires only minimal filtering after the rectifiers.

FIG. 25B AC rectifier and filter sub-circuit OUTB

FIG. 25B is a schematic diagram of an alternate final output rectifierand filter sub-circuit OUTB. The rectifier sub-circuit OUTB comprisesdiodes D40, D41, D42 and D43 and capacitor C931 and C928.

FIG. 25B Table Element Value/part number D40 40CTQ150 D41 40CTQ150 D4240CTQ150 D43 40CTQ150 C928 .01 uf C931 10,000 uf

An AC or DC signal is connected to nodes C7B and C8b. Node C7B connectsdiode D41 anode to D40 cathode. Node C8b connects diode D42 anode to D43cathode. Node OUT+ connects diode D42 cathode to D43 cathode. Node OUT−connects diode D40 anode to D43 anode. Diodes are selected to reliablyblock the expected line voltage and current demands of the load. For lowvoltage outputs, Schottky type diodes are used due to their low forwardvoltage drop. Higher voltages would use high-speed silicon diodes due totheir ability to withstand high peak inverse voltage (PIV). The use ofthe NSME for the push-pull magnetic element requires only minimalfiltering after the rectifiers. Capacitor C928 is shown schematically asa single device. Capacitor C931 is a larger polarized selected for lowimpedance to low frequency signals and for energy storage a typicalvalue may be 200 uF. To increase the capacitance or reduces the outputimpedance multiple capacitors may be used. C931 is a solid dielectrictype and is selected for it's low impedance to high frequencies. As isselected to reduces noise for a particular operating frequency and powerlevel. Capacitor C928 is selected for the operating frequency and powerlevel. Sub-circuit OUTB performs AC to DC rectification and filtering atslightly lower efficiency due to the extra junctions.

FIG. 26 Floating 18_Volt DC control power sub-circuit CP Sub-circuit CPconsists of diodes D501, D502 and D503, resistor R507, regulator Q504,and capacitors C503, C504, C505, C506, and C507.

FIG. 26 Table Element Value/part number C503 .33 uF C504 100 uF D501MURS120T3 C505 .33 uf Q504 LM7818A C508 100 uf C507 100 uf D503MURS130T3 D502 MURS120T3

Node CT1A connects to anode of D503 and to the upper external centertapped secondary winding. Node CT2A connects to anode of D502 and to thelower external center tapped secondary winding. Node CT0 connects to theexternal winding center tap. Node CT0 is also the return line and itconnects to Q504 pin 2, and capacitors C503, C504, C505, C506, and C507.The cathode of each of diodes D502 and D503 is connected to resistorR507. R507 is then connected to the pin 1 (input) node of voltageregulator Q504. Voltage regulator Q504 Pin 3 is the 18 vdc regulated DCoutput is connected to the anode of blocking diode D501. Three-pinvoltage regulator Q504 is of the type LM7818 a common device made by anumber of manufacturers. Capacitors C503, C505, C506 are 0.1 uF soliddielectric type and are used to filter high frequency ripple and toprevent Q504 from oscillating. The junction of C503, C504 and D501cathode is the output node CP1+. Isolated 18-volt DC is availablebetween nodes CT0 and CP+ Used for regulator circuits and output switchdrive during normal operation.

FIG. 27 second Floating 18_Volt DC push-pull control power sub-circuitCPA. Sub-circuit CPA consists of diodes D601, D602 and D603, resistorR607, regulator B604 and capacitors C603, C604, C605, C606, C607 andC608.

FIG. 27 Table Element Value/part number C603 .33 uF C604 100 uF D601MURS120T3 C605 .33 uF Q604 LM7818A C608 100 uF C607 .22 uF R607 7.5 ohmsD603 MURS120T3 D602 MURS120T3

Node CT1B connects to anode of D603 and to the upper external centertapped secondary winding. Node CT2B connects to anode of D602 and to thelower external center tapped secondary winding. Node CT20 connects tothe external winding center tap. Node CT0 is also the return line and itconnects to Q604 pin 2, and capacitors C603, C604, C605, C606, and C607.The cathode of each of diodes D602 and D603 is connected to resistorR607. R607 is then connected to the pin 1 (input) node of voltageregulator Q604. Voltage regulator Q604 Pin 3 is the 18vdc regulated DCoutput and is connected to the anode of blocking diode D601. CapacitorsC603, C605, C606 are solid dielectric type and are used to filter highfrequency ripple and to prevent Q604 from oscillating. The junction ofC603, C604 and D601 cathode is the output node CP1+. Isolated 18-volt DCis available between nodes CT20 and CP2+. To be used for regulatorcircuits and output switch drive during normal operation.

FIG. 28 over temperature protection sub-circuit OTP

FIG. 28 is the main switch over temperature protection sub-circuit OTP.The sub-circuit OTP comprises thermal switch and resistors R711 andR712.

FIG. 28 Table Element Value/part number THS1 67F105 (105C) R711 20 ohmsR712 20 ohms

Gate drive power is applied to input node GAP and to thermal switchTHS1. Maximum FET gate voltage requires the input power voltage be lessthan 20 volts, the voltage selected was 18 volts. The other side of THS1is connected to parallel resistors [R711||R712]. A single resistor mayrepresent the resistors. The figure depicts the surface mountarrangement. The other side of [R711||R712] connects to output node TS+.Normally closed thermal switch TS1 is in contact with main switchtransistor Q1. In the event of temperature greater than 105C THS1 opens,thus removing power to the buffer sub-circuit AMP1 (FIG. 29) causingswitch Q1 to default to a blocking state protecting the boost switchshould the optional cooling fan fail or the circuit reach hightemperatures. In this instant invention the speed up buffer AMP (FIG.29) non-saturating magnetics (FIGS. 18, 18A and 19) allows the mainswitch and to run cooler than prior art for a given power level. Whenswitch temperature returns to normal range THS1 will close, allowing thePFC to resume normal operation. Under normal load and ambienttemperatures the thermal switch THS1 should never open.

FIG. 29 PFC Buffer Circuit sub-circuit AMP, AMP1, AMP2, AMP3

Switch drive command from PFCLK (FIGS. 23 and 24) or PWFM (FIG. 33)control elements are connected to a gate buffer circuit. The sub-circuitAMP is comprised of power FET Q702, Darlington pair Q703, capacitorsC709 and C715, and resistors R710 and R725.

FIG. 29 Table Element Value/part number C715 1000 pf C709 33 uF Q702NOS355NCT Q703 FZT705CT R710 0 ohms R725 22.1k ohms

DC Power is applied to node GAT+ to transistor Q702 drain and tocapacitor C709, which goes to ground. Maximum gate voltage requires theinput power voltage must be less than 20 volts, 18-volts was selected.Input node GA1 is connected to the gate of FET Q702 is connected to thebase of BJT1 of the Darlington pair Q703 and to capacitor C715. C715 isconnected across the Darlington pair from the base, pin 1, to thecollectors, pins 2 and 4, Q703 collector node is also connected toground. The emitter of BJT2 is connected to the gate of FET Q1. Thesource of FET Q702 is connected through small optional series resistorR710 to the gate of the output switch or node GA2. Some power FET'sunder certain load may tend to oscillate when driven from a lowimpedance source such as this buffer. A small resistance ofapproximately 2 ohms or less may be required with out significantslowing of the switch. In most cases R710 is replaced with a zero ohmjumper. Resistor R725 is connected from node GA0 and source of Q702. Theinput switching signal to node GAP is in range of 20 kHz to 600 kHz.Very fast “on” times are realized by proving a low impedance to rapidlycharge the output switch gate connected to node GA2. Capacitor C709provides additional current when Q702 switches on. Transistor Q703provides low impedance to rapidly remove the charge from the gategreatly reducing the “off” time. This particular topology providesoutput switch rise times on the order of 10 ns, as compared to theindustry standard rise time of 250 ns. The corresponding fall time is<10 nS, again as compared to an industry fall time of 200-300 ns (SeeFIGS. 13 and 14). In the event the converter is operated at very highambient temperatures a thermal switch may be placed in series with inputpower pin GA+. This allows the switch transistor to be gracefullydisabled. Sub-circuit AMP greatly reduces switching losses allowingconverter operation in some cases with out the common prior art forcedair-cooling.

FIG. 30 snubber sub-circuit SN

FIG. 30 is a schematic diagram of a snubber sub-circuit of theinvention. The snubber sub-circuit SN is comprised of diodes D804 andD805 and resistors R800, R817, R818, and capacitors C814 and C819.

FIG. 30 Table Element Value/part number R800 12 ohms R817 1 mohm R818 1mohm C814 33 pF C819 560 pF D805 MUR160

Node SNL2 connects to the drain terminal of the external output switchand to flyback side of the inductive load. Input node SNL2 connects toR800 in series with capacitor C819 to node SNOUT. Diode D805 anode isconnected to node SNL2 with resistors [R817||R818] in parallel withD805. Resistors R817 and R818 may be combined to a single resistor. Thecathode of D805 is connected to capacitor C814 that connects to node/pinSNL1. Node SNL1 connects to the supply side of external load magneticelement. The other leg of external magnetic element is connected to theanode of D805 and the anode side of external flyback diode D4. The oneMEG ohm resistors R817 and R818 bleed the charge from C814 resetting itfor the next cycle. Capacitor C819 and resistor R800 captures the highfrequency event from the transition of external flyback diode D4 andmoves part of the energy into the external holdup capacitor connected tonode SNOUT. Since external flyback diode D4 and D805 isolate the drainof the output switch, faster switching occurs because the output switchdoes not have to slew the extra capacitance of a typical drain/sourceconnected snubber circuit. Note that this circuit does not attempt toabsorb the flyback in large RC networks that convert useful energy tolosses. Nor does it attempt to stuff the flyback to ground, addingcapacitance and slowing the output switch and increasing switchinglosses. This sub-circuit is used with it's mirror SNB (FIG. 32) acrossthe external push-pull switches. This design returns the some of theflyback energy back to the input supply or output load. The “snubbering”action slows the rise of the flyback giving time for the externalflyback diode to start conduction. The circuit efficiently manages highfrequency flyback pulses.

FIG. 30A diode snubber sub-circuit DSN

FIG. 30A is a schematic diagram of a diode snubber sub-circuit of theinvention. The snubber sub-circuit DSN is comprised of diodes D51, D52,D53, D54 and D55 and capacitors C51, C52, C53, C54 and C55.

FIG. 30A Table Element Value/part number C51 220 pf 100 v C52 220 pf 100v C53 220 pf 100 v C54 220 pf 100 v C55 220 pf 100 v D51 Schottky 1-2 ns100 v SMBSR1010MSCT D52 Schottky 1-2 ns 100 v SMBSR1010MSCT D53 Schottky1-2 ns 100 v SMBSR1010MSCT D54 Schottky 1-2 ns 100 v SMBSR1010MSCT D55Schottky 1-2 ns 100 v SMBSR1010MSCT

Pin SNL2 is connected to the anode of D51 the cathode of D51 isconnected to the anode of D52 the cathode of D52 is connected to theanode of D53 the cathode of D53 is connected to the anode of D54 thecathode of D54 is connected to the anode of D55 the cathode of D55 isconnected to pin SNOUT. Capacitors are connected across each diodeforming a series parallel combination of[D51||C51]+[D52||C52]+[D53||C53]+[D54||C54]+[D55||C55]. Node SNL2connects to the drain terminal of the external output switch and toflyback side of the inductive load. The external fly-back rectifierdiode D4 (FIGS. 1, 3 and 4) anode is connected to node SNL2. Node SNOUTconnects to the storage capacitors [C16||C17] (FIGS. 1, 3 and 4) and tothe cathode of the flyback diode D4. External diode D4 in parallel withDSN forms a hybrid diode. The Schottky diode has the desirablecharacteristics of fast recovery time (less than 6 nanoseconds(6*10{circumflex over ( )}−9)) and low forward voltage drop (0.4-0.9Volts) at high currents. The Schottky diode suffers from limited reverseblocking voltage currently 100 V maximum. Each diode will block 100V;the parallel capacitors distribute the reverse voltage equally acrossthe diode string. As the reverse junction capacitance of each diode isless than 10 pf much smaller than the parallel capacitor. Thus thereverse voltage is nearly equally divided across the diodes. Toguarantee even voltage division 5% or better capacitor matching isrequired. High precision is common and inexpensive for small capacitors.Different blocking voltages may be achieved by adjusting the number ofdiode/capacitor pairs. By way of example not as a limitation 500V wasselected. The main fly-back rectifier diode D4 will block high voltagesbut suffers from long reverse recovery time 50-500 nanoseconds is commonin fast recovery diodes. What is needed is a diode with low voltagedrop, high blocking voltage and very short recovery time. The snubberDSN in parallel with the main fly-back rectifier comes very close tothat ideal diode. The total blocking voltage is achieved by the addingthe individual diode blocking voltages. The recovery time is determinedby the slowest diode in the string often less than 5 nanoseconds. Thelow forward voltage drop is achieved when the slower main rectifierbegins conduction. Low capacitance is also realized, as the capacitanceis ⅕ of the individual capacitors. This hybrid diode beginsrectification immediately after the main switch stops conduction and thenon-saturating magnetic begins releasing its energy. This effectivelylimits the high voltage flyback over shoot to less than 40-70 volts.This keeps the switch well inside it's safe operating area (SOA)allowing the switch to be run at higher voltages for higher output powerand additional efficiency gain, or to use a less expensive lower voltageswitch while keeping the same voltage margins. Since external flybackdiode D4 and D805 isolate the drain of output switch, faster switchingoccurs because the output switch does not have to slew the extracapacitance of the typical snubber circuit. Note that this circuit doesnot attempt to absorb the flyback in large RC networks that generateadditional heat. Nor does it attempt to stuff the flyback to ground,adding capacitance and slowing the output switch, increasing switchinglosses. Sub-circuit DSN may be used in parallel with any slowerrectifier such as flyback diode D4 to assist the main rectifier. Thisproviding additional protection to the switch and rectifying the portionof the flyback pulse before the main rectifier begins condition. Thathigh frequency energy ends up as heat or radiated noise.

FIG. 31 snubber sub-circuit SNA

FIG. 31 is a schematic diagram of a snubber sub-circuit of theinvention. The snubber sub-circuit SNA is comprised of resistor R810 andR811 and capacitors C820 and C821.

FIG. 31 Table Element Value/part number R810 500 pF C811 330 pF C820 12ohm C821 10 ohm

Node SNA1 connects to series resistor R810 to capacitor C820 to nodeSNA2 then to capacitor C821 and series resistor R811 to node SNA3. NodeSNA1 connects to the external magnetic element center tap. Node SNA2connects to the drain terminal of the external output switch and toflyback side of the inductive load. Node SNA3 connects to the sourceterminal of the external output switch. Resistor R810 and C820 attemptto absorb part of the flyback to reduce voltage transients across theswitch. Part of the flyback is returned to ground by C821. Thissub-circuit is used with it's mirror SNA (FIG. 31) across the externalpush-pull switches. The “snubbering” action slows the rise of theflyback giving time for the external rectifier diodes D8 and D9 of FIG.25 or 25A to start conduction. The circuit efficiently manages highfrequency flyback pulses.

FIG. 32 snubber sub-circuit SNB

FIG. 32 is a schematic diagram of a snubber sub-circuit of theinvention. The snubber sub-circuit SNB comprises resistor R820 and R821and capacitors C840 and C841.

FIG. 32 Table Element Value/part number C840 500 pF C841 330 pF R820 12ohm R821 10 ohm

Node SNB1 connects to series resistor R820 to capacitor C820 to nodeSNA2 to capacitor C841 and to series resistor R821 to node SNB3. NodeSNB1 connects to the external magnetic element center tap. Node SNB2connects to the drain terminal of the external output switch and toflyback side of the inductive load. Node SNB3 connects to the sourceterminal of the external output switch. Resistor R820 and C840 attemptto absorb part of the high frequency flyback to reduce voltagetransients across the switch. C841 and R821 return part of the flybackto ground. The “snubbering” action slows the rise of the flyback givingtime for the external rectifier diodes D8 and D9 of FIG. 25 or 25A tostart conduction. The circuit efficiently manages high frequency flybackpulses.

FIG. 33 Pulse/Frequency modulator PWFM

FIG. 33 is the inventions PWM (pulse width modulator) and FM (frequencymodulator) sub-circuit. Sub-circuit PWFM consists of resistors R401,R402, R403, and R404 capacitors C401, C402, C403, C404, C405 and C406,controller IC U400 and diode D401.

FIG. 33 Table Element Value/part number R404 50k ohms C406 100 uf C4010.22 uF C403 0.01 uF C405 2200 pF C404 470 pF C402 0.22 uF R403 50k ohmsD401 RLS139 (low leakage) R401 2.2 MEG ohms R402 150k ohms U400 MIC38C43

Control element U400 connects to a circuit with the following seriesconnections: from pin 1 to feedback pin PW1 then to the wiper ofadjustable resistor R404 to return node PWFM0. Resistor R404 may bereplaced with two fixed resistors. Capacitor C403 is connected from pin2 to pin 1. Capacitor C403 is used to filter the error amp output. Theupper half of resistor R404 is connected to node REF1 pin 8 the 5.0-Voltinternal reference. Internal 5.0-volt reference U400 pin 8 or Node REF1is connected to the upper half of resistor R403 and through capacitorC402 to return node PWFM0. The reference provides current to externalfeed back networks. Wiper of R403 connects to node FM1 to pin 4, throughR402 to pin 3, and through C404 to return node PWFM0. Resistor R403 maybe replaced with two fixed resistors. Pulse width timing capacitor C404connects pin 3 to return node PWFM0. Low leakage diode D401 anode isconnected to pin 3 cathode to output pin 6 node CLK. Resistor R404 setsthe nominal pulse width of output pin 6 node CLK. The pulse width can beadjusted from 0 (off) to 95%. Resistor R403 and C404 determine thenominal operating frequency. With application of power 20-volts betweenNodes PWFM+ and PRFM0 controller U400 generates an internal 5.0reference voltage to pin 7 node REF1. Output pin 6 node CLK is set highapproximately 20-volts (see oscillograph trace G6 segment 60 FIG. 34).C404 starts to charge through R401 until the voltage across C404 at pin3 reaches the comparator level (see oscillograph trace G1 segment 61FIG.34) at resetting the pin 6 low (see oscillograph trace G6 segment 62FIG. 34). Capacitor C404 rapidly discharges though D401 (seeoscillograph trace G1 segment 63 FIG. 34). Pin 3 remains 0.6-volts abovePRFM0 node during the period pin 6 is low (see oscillograph trace G1segment 64 FIG. 34). On the rising edge of pin 6 capacitor C405 beginsto rapidly charge until the voltage in pin 4 reaches the internalcomparator level (see oscillograph trace G4 segment 65 FIG. 34). Thecomparator triggers internal transistor to rapidly discharge C404 (seeoscillograph trace G4 segment 66 FIG. 34). The cycle repeats with outputpin 6 being set high. External feedback current applied to U400 pin 1and node PW1 (see oscillograph trace G1 segment FIG. 34) follows theactual output voltage. Oscillograph trace G1 segment 67 (FIG. 34) is theperiod when the output switch conducting storing energy in the NSME.Oscillograph trace G1 segment 68 (FIG. 34) is the period when the outputswitch is off allowing storing energy in the NSME to be transferred tothe storage capacitor. Application of external current source or feedback network to pin 1 or node PW1 allows the pulse width to bemodulated. Removing current from PW1 lowers the comparator level causingthe comparator to trigger at lower voltages across C404 reducing thepulse width. Introducing current into node PW1 increases pulse widthfrom nominal to maximum of 95%. Resistor R404 and C404 determine thenominal pulse width. This design allows the CLK output to be pulse widthmodulated. Application of external feed back network to pin 4 or nodeFW1 allows the frequency to be modulated. Removing current from FW1slows the charging of C405. Longer charging time lowers the frequencyfrom the nominal setting. This arrangement allows the CLK output tofrequency modulated. When used with a resonant controller, R403 and C405determine the nominal frequency typically equal to the tank resonantfrequency. The external feedback is configured to lower the frequencyfrom nominal (maximum output) to zero frequency “off”. When used as apulse-width controller the nominal is set to maximum pulse width ofabout 90% feedback reduces the pulse-width. Sub-circuit PWFM may besimultaneously frequency and pulse width modulated. This configurationand mode of operation is unique to this instant invention. Feeding backof the output to the error amplifier is a unique mode of operation forcontrol element U400. Sub-circuit PWFM combines large dynamic range,precise control and fast response.

FIG. 34 Oscillograph traces of the PWFM (FIG. 33) controller in thepulse-width modulation mode.

FIG. 35 Oscillograph trace of the TCTP (FIG. 8) resonant converterprimary voltage. FIG. 35 is an oscillograph trace of the voltagedeveloped across capacitor C10 (FIG. 8). In this embodiment the supplyVBAT was only 18-volts. The primary 100 (FIG. 18) inductance 203 uH wasachieved by 55 turns on a 26 u 2.28 oz. KoolMu magnetic element 101. Thesecondary winding 103 (FIG. 18) is 15 turns on core 101. A 5.5-watt loadis connected to winding 103. The NSME primary 100 (FIG. 18) developed anexcitation voltage of 229 volts peak more than 10 times VBAT. Tankconverters TCTP and TCSSC (FIG. 7) take advantage of the desirableproperties of the non-saturating magnetic to develop large flux biases.The useful large flux may harvested into useful power by addition of“flux nets” windings to the magnetic element.

FIG. 36 Regulated 18_Volt DC control power sub-circuit REG Sub-circuitREG consists of resistor R517, regulator Q514 and capacitors C514, C515,C516, C518, and C517.

FIG. 36 Table Element Value/part number Q514 LM7818 C515 0.1 uF C517 0.1uF C514 10 uF C518 10 uF

Pin REG0 connects to the external power source return. Node REG0 is alsothe return line it connects to Q514 pin 2, and capacitors C518, C514,C515, and C517. Resistor R517 is connected to the pin 1 (input) node ofvoltage regulator Q514 and to input pin RIN+. Voltage regulator Q514 Pin3 is the 18vdc regulated DC output is connected to the capacitors C515,C514 and output pin 18V. Capacitors C515, C517 are solid dielectric typeis used to filter high frequency ripple and to prevent Q514 fromoscillating. Sub-circuit REG provides regulated power for controlcircuits and output switch buffer AMP (FIG. 29).

FIG. 37 is a schematic for a non-isolated high side switch buckconverter sub-circuit HSBK. FIG. 37 is a non-isolated high side switchbuck converter sub-circuit HSBK. This converter topology consists of anon-isolated high efficiency buck stage, which provides regulated powerto an efficient push-pull isolation stage. Sub-circuit HSBK consists ofdiode D8, capacitor C8, FET transistor Q31, sub-circuit TCTP (FIG. 8),sub-circuit BL1 (FIG. 18B), sub-circuit IFB (FIG. 40B), sub-circuit AMP(FIG. 29) and sub-circuit PWFM (FIG. 33).

FIG. 37 Table Element Value/part number C68 250 uf D68 MUR820 Q31IRF540N

External power source VBAT connects to pins DCIN+ and DCIN−. Pin DCIN+connects to transistor Q31 source, sub-circuit PWFM pin PRFM0,sub-circuit AMP pin GA0, and sub-circuit IFB pin FBE, sub-circuit TCTPpins DCIN+ and B−. Regulated 18-volt output from sub-circuit TCTP pin B+connects to sub-circuit AMP pin GA+ and to sub-circuit PWFM pin PWFM+.This provides the positive gate drive relative to the source of Q31.Power source VBAT return is connected to pin DCIN−, sub-circuit TCTP pinDCIN−, diode D68 anode, capacitor C68, RLOAD, sub-circuit IFB pin OUT−,output pin B− and ground/return node GND. Sub-circuit PWFM is designedfor adjustable pulse-width operation from 0 to 90%, maximum pulse widthoccurs with no feedback current to pin PW1. Increasing the feedbackcurrent reduces the pulse-width and output voltage from converter HSBK.Sub-circuit PWFM clock/PWM output pin CLK is connected to the input pinGA1 of buffer sub-circuit AMP. The output of sub-circuit AMP pin GA2 isconnected to the gate of Q31. The drain of Q31 is connected tosub-circuit BL1 pin P1B and the cathode of D68. Pin P1A of sub-circuitBL1 is connected to capacitor C8, sub-circuit IFB pin OUT− and RLOAD.With sub-circuit PWFM pin CLK high buffer AMP output pin GA2 charges thegate of transistor switch Q31. Switch Q31 conducts charging capacitorC68 through NSME BL1 from source VBAT and storing energy in BL1.Feedback output pin FBC from sub-circuit IFB is connected to sub-circuitPWFM pulse-width adjustment pin PW1. As the output voltage reaches thedesigned level sub-circuit IFB removes current from PW1 commanding PWFMto reduce the pulse-width or on time of signal CLK. After sub-circuitPWFM reaches the commanded pulse-width PWFM switches output pin CLK lowturning off Q31 stopping the current into BL1. The stored energy isreleased from NSME BL1 into the now forward biased diode D68 chargingcapacitor C68. By modulating the on time of switch Q31 the converter“bucks” applied voltage and efficiently regulates to a lower voltage.Regulated voltage is developed across Nodes B− and B+. Sub-circuit IFBprovides the isolated feedback voltage to the sub-circuit PWFM. Whensub-circuit IFB senses the converter output (nodes B+ and B−) is at thedesigned voltage more current is conducted by the phototransistor.Sinking current from PM1 commands the PWFM to a shorter pulse-width thusreducing the converter output voltage. In the event the feedback signalfrom IFB commands the PWFM to minimum output. Gate drive to switch Q31is removed stopping all buck activity capacitor C68 discharges throughRLOAD. Input current from VBAT is sinusoidal making the converter veryquiet. As such the switch Q31 is not exposed to large current spikescommon to saturating magnetic prior art. Thus placing less stress on theswitches thereby increasing the MTBF. Sub-circuit HSBK takes advantageof the desirable properties of the NSME in this converter topology.

FIG. 38 is a schematic for an isolated two-stage low side switch buckconverter sub-circuit LSBKPP. This converter topology consists of a highefficiency low-side switch buck stage, which provides regulated power toan efficient push-pull isolation stage. An efficient center-tap fullwaverectifier provides rectification. Sub-circuit LSBKPP consists of diodeD46, capacitor C46, FET transistor Q141, sub-circuit REG (FIG. 36),sub-circuit OUTB (FIG. 25A), sub-circuit BL1 (FIG. 18B), sub-circuitTCTP (FIG. 8), sub-circuit IFB (FIG. 40B), sub-circuit AMP (FIG. 29),sub-circuit DCAC1, and sub-circuit PWFM (FIG. 33).

FIG. 38 Table Element Value/part number C46 250 uf D46 MUR820 Q141IRF540N

External power source VBAT connects to pins DCIN+ and DCIN−. From pinDCIN+ connects to sub-circuit REG pin RIN+, D46 cathode, capacitor C46,sub-circuit TCTP (FIG. 8) pin DCIN+, and sub-circuit DCAC1 pin DC+.Voltage regulator sub-circuit REG output pin +18V connects tosub-circuit AMP pin GA+ and to sub-circuit PWFM pin PWFM+. Sub-circuitREG provides regulated low voltage power to the controller and to themain switch buffer. VBAT negative is connected to pin DCIN− and groundreturn node GND. Node GND connects to sub-circuit PWFM pin PRFM0,sub-circuit AMP pin GA0, Q141 source, sub-circuit IFB pin FBE,sub-circuit REG pin REG0 and sub-circuit TCTP pin DCIN−. Sub-circuitPWFM (FIG. 33) is designed for variable pulse width operation. Thenominal frequency is between 20-600 Khz PWFM is configured for maximumpulse width 90% (maximum buck voltage) with no feedback current fromsub-circuit IFB. Increasing the feedback current reduces the Q111 ontime reducing the voltage to the push-pull stage and the output fromconverter LSBKPP. Sub-circuit PWFM clock output pin CLK is connected tothe input pin GA1 of buffer sub-circuit AMP (FIG. 29). The output ofswitch speed up buffer sub-circuit AMP pin GA2 is connected to the gateof Q141. Floating isolated 18-volt power from sub-circuit TCTP pin B+connects to sub-circuit DCAC1 pin P18V. The drain of Q141 is connectedto sub-circuit BL1 pin P1A and the anode of D46. The return line ofsub-circuit DCAC1 pin DC− connects to sub-circuit BL1 pin P1B,sub-circuit TCTP pin B− and C46. With sub-circuit PWFM pin CLK highbuffer AMP output pin GA2 charges the gate of transistor switch Q141.Switch Q141 conducts reverse biasing diode D46; capacitor C46 startscharging through NSME BL1 from source VBAT. During the time Q141 isconducting, energy is stored in NSME sub-circuit BL1. Charging C46provides power to final push-pull converter stage DCAC1. The output ofthe output rectifier sub-circuit OUTB is connected to feedbacksub-circuit IFB output pin FBC from sub-circuit IFB is connected tosub-circuit PWFM pulse-width adjustment pin PW1. Sub-circuit IFB removescurrent from PW1 commanding PWFM to reduce the pulse-width or on time ofsignal CLK. After sub-circuit PWFM reaches the commanded pulse-widthPFFM switches CLK low turning off Q141 stopping the current into BL1.The energy is released from NSME BL1 into the now forward biased flybackdiode D46 charging capacitor C46. By modulating the on time of switchQ141 the converter voltage is regulated. Regulated voltage is developedacross C46 Nodes DC+ and GND. Providing energy to the isolated constantfrequency push-pull DC to AC converter sub-circuit DCAC1 (FIG. 2).Sub-circuit DCAC1 provides efficient conversion of the regulated buckvoltage to a higher or lower voltage set by the magnetic element windingsub-circuit PPT1 (FIG. 19) ratio. The center tap of the push-pull outputmagnetic is connected to, sub-circuit OUTB pin OUT−, RLOAD, sub-circuitIFB pin OUT− and the pin OUT− forming the return line for the load andfeedback network. Output of sub-circuit DCAC1 pin ACH is connected tosub-circuit OUTB pin C7B. Output of sub-circuit DCAC1 pin ACL isconnected to sub-circuit OUTB pin C8B. Sub-circuit OUTB providesrectification of the AC power generated by sub-circuit DCAC1. As thenon-saturation magnetic converter is very quite minimal filtering isrequired by OUTB. This further reduces cost and improves efficiency aslosses to filter components are minimized. Sub-circuit IFB provides theisolated feedback current to the sub-circuit PWFM. When sub-circuit IFBsenses the converter output (nodes OUT+ and OUT−) is greater than thedesigned/desired voltage, current is removed from node PM1. Sinkingcurrent from PM1 commands the PWFM to a shorter pulse-width thusincreasing the buck action and reducing the first stage converter outputvoltage. In the event the feedback signal from IFB commands the PWFM tominimum output. Gate drive to switch Q141 is removed stopping all buckactivity capacitor discharging C46. Input current from VBAT to chargeC46 is sinusoidal making the converter very quiet. In addition theswitch Q141 is not exposed a potentially destructive current spike.Placing less stress on the switches thereby increasing the MTBF.Sub-circuit LSBKPP takes advantage of the desirable properties of theNSME in this converter topology. Adjusting the NSME BL1 (FIG. 18B) setsthe amount of buck voltage available to the final push-pull isolationstage. Greater efficiencies are achieved at higher voltages. The finaloutput voltage is set by the turns ratio of the push-pull element PPT1(FIG. 19). Converter LSBKPP provides efficient conversion from highvoltage sources into high current isolated output.

FIG. 39 is a schematic for an isolated two-stage low side switch buckconverter sub-circuit LSBKPPBR. This converter topology consists of anon-isolated high efficiency low-side switch buck stage, which providesregulated power to an efficient push-pull isolation stage. A fullwavebridge rectifier provides rectification. Sub-circuit LSBKPPBR consistsof diode D6, capacitor C6, FET transistor Q111, sub-circuit REG (FIG.36), sub-circuit OUTBB (FIG. 25B), sub-circuit BL1 (FIG. 18B),sub-circuit TCTP (FIG. 8), sub-circuit IFB (FIG. 40B), sub-circuit AMP(FIG. 29), sub-circuit DCAC1 (FIG. 2), and sub-circuit PWFM (FIG. 33).

FIG. 39 Table Element Value/part number C6 250 uf D6 MUR820 Q111 IRFP

External power source VBAT connects to pins DCIN+ and DCIN−. From pinDCIN+ connects to sub-circuit REG pin RIN+, D6 cathode, capacitor C6,sub-circuit TCTP (FIG. 8) pin DCIN+, and sub-circuit DCAC1 pin DC+.Voltage regulator sub-circuit REG output pin +18V connects tosub-circuit AMP pin GA+ and to sub-circuit PWFM pin PWFM+. Sub-circuitREG provides regulated low voltage power to the controller and to themain switch buffer. VBAT negative is connected to pin DCIN− connects tosub-circuit PWFM pin PRFM0, sub-circuit AMP pin GA0, Q111 source,sub-circuit IFB pin FBE, sub-circuit REG pin REG0, sub-circuit TCTP pinDCIN−. Sub-circuit PWFM (FIG. 33) is designed for variable pulse widthoperation. The nominal frequency is between 20-600 Khz PWFM isconfigured for maximum pulse width 90% (maximum buck voltage) with nofeedback current from sub-circuit IFB. Increasing the feedback currentreduces the Q111 on time reducing the voltage to the push-pull stage andthe output from converter LSBKPPBR. Sub-circuit PWFM clock output pinCLK is connected to the input pin GA1 of buffer sub-circuit AMP (FIG.29). The output of switch speed up buffer sub-circuit AMP pin GA2 isconnected to the gate of Q111. Floating isolated 18-volt power fromsub-circuit TCTP pin B+ connects to sub-circuit DCAC1 pin P18V. Thedrain of Q111 is connected to sub-circuit BL1 pin PA1 and the anode ofD6. The return line of sub-circuit DCAC1 pin DC− connects to sub-circuitBL1 pin P1B, sub-circuit TCTP pin B− and C6. With sub-circuit PWFM pinCLK high buffer AMP output pin GA2 charges the gate of transistor switchQ111. Switch Q111 conducts reverse biasing diode D6; capacitor C6 startscharging through NSME BL1 from source VBAT. During the time Q111 isconducting, energy is stored in NSME sub-circuit BL1. Charging C6provides power to final push-pull converter stage DCAC1. The output ofthe output rectifier sub-circuit OUTBB is connected to feedbacksub-circuit IPB output pin FBC from sub-circuit IFB is connected tosub-circuit PWFM pulse-width adjustment pin PW1. Sub-circuit IFB removescurrent from PW1 commanding PWFM to reduce the pulse-width or on time ofsignal CLK. After sub-circuit PWFM reaches the commanded pulse-widthPFFM switches CLK low turning off Q111 stopping the current into BL1.The energy is released from NSME BL1 into the now forward biased flybackdiode D6 charging capacitor C6. By modulating the on time of switch Q111the converter voltage is regulated. Regulated voltage is developedacross C6 nodes DC+ and DC−. Providing energy to the isolated constantfrequency push-pull DC to AC converter sub-circuit DCAC1 (FIG. 2).Sub-circuit DCAC1 provides efficient conversion of the regulated buckvoltage to a higher or lower voltage set by the magnetic element windingsub-circuit PPT1 (FIG. 19) ratio. The return node of the sub-circuitOUTBB pin OUT− is connected to RLOAD, sub-circuit DCAC1 pin AC0,sub-circuit IFB pin OUT− and the pin OUT−. Node OUT− is the return linefor the load and feedback network. Output of sub-circuit DCAC1 pin ACHis connected to sub-circuit OUTBB pin C7B. Output of sub-circuit DCAC1pin ACL is connected to sub-circuit OUTBB pin C8B. Sub-circuit OUTBBprovides rectification of the AC power generated by sub-circuit DCAC1.As the disclosed non-saturation magnetic converter has minimal outputripple, less filtering is required by OUTBB. This further reduces costand improves efficiency as losses in filter components are minimized.Sub-circuit IFB provides the isolated feedback current to thesub-circuit PWFM. Open collector output of IFB pin FBC connects to PWFMpin PW1. When sub-circuit IFB senses the converter output (nodes OUT+and OUT−) is greater than the designed/desired voltage, current isremoved from node PM1. Sinking current from PM1 commands the PWFM to ashorter pulse-width thus increasing the buck action and reducing thefirst stage converter output voltage. In the event the feedback signalfrom IFB commands the PWFM to minimum output. Gate drive to switch Q111is removed stopping all buck activity capacitor discharging C6. As theNSME does not saturate the destructive noisy current spikes common toprior art are absent. Input current from VBAT to charge C6 is sinusoidalmaking the converter very quiet. In addition the switch Q111 is notexposed a potentially destructive current spike. Placing less stress onthe switches thereby increasing the MTBF. Sub-circuit LSBKPPBR takesadvantage of the desirable properties of the NSME in this convertertopology. Adjusting the NSME BL1 (FIG. 18B) sets the amount of buckvoltage available to the final push-pull isolation stage. Greaterefficiencies are achieved at higher voltages. The final output voltageis set by the turns ratio of the push-pull element PPT1 (FIG. 19).Converter LSBKPPBR provides efficient conversion from high voltagesources such as high power factor AC to DC converters such assub-circuit ACDCPF (FIG. 4).

FIG. 40 PFC over voltage feed back sub-circuit IPFFB

FIG. 40 is the schematic of the inventions isolated over voltage feedback network sub-circuit IPFFB. Sub-circuit IPFFB consists of ResistorsR926, R927, R928, R929 and R930, capacitor C927, zener diodes D928 andD903, transistor Q915 and opto-isolator U903.

FIG. 40 Table Element Value/part number U903 NEC2501 Q915 FZT705CT D903ML5248B (18v) D928 1SMB5956BT3 (200v) R926 20k ohms R927 10k ohms R92810k ohms R929 10k ohms R930 20k ohms

Node PF+ connects through resistor R927 to cathode of D903 and anode ofopto-isolator U903. Cathode of diode D903 is connected to pin PF+.Resistor R928 is connected from anode of D928 to base of Q915. CapacitorC927 is connected in parallel with zener diode D903. Resistor R928limits maximum base current. Resistor R929 is connected between base andemitter of Q915. Resistor R929 is used to shunt excess zener leakagecurrent from the base common in high voltage diodes. Two hundred-voltzener diode cathodes D928 are connected to pin PF+. Anode of D928 isconnected to R930 and R928. Resistor R930 provides a path for leakagecurrent from 200-volt zener D928. Resistor R926 limits the maximumcurrent to U903 internal light emitting diode to about 10 ma. ResistorR927 sets the maximum zener current at maximum boost voltage ofapproximately 200-volts to 20 ma. Transistor Q915 is biased off when thevoltage from node PF+ and PF− is less than the zener voltage of200-volts. Transistor is in a cutoff or non-conducting state no currentis injected to U903 LED. The internal phototransistor is also in anon-conducting state. The attached external control sub-circuit is notcommanded to change its output. With 200 volts or more applied to nodesPF+ and PF− reverse biased zener diode D928 injects current into thebase of Q915. Resistor R927, capacitor C927 and diode D903 provide18-volts to the collector of Q915. Transistor Q915 conducts current intoU903 LED injecting base current into the U903 phototransistor.Modulating the LED current is reflected as variable impedance betweenFBC and FBE. This phototransistor may be connected as a variable currentsource or impedance. This sub-circuit senses excessive boost voltage andquickly feeds back to the control sub-circuit (See PFA (FIG. 23), PFB(FIG. 24) or (PWFM FIG. 33)) automatically reducing the boost voltage.

FIG. 40A is a schematic diagram of the non-isolated boost output voltagefeed back sub-circuit FBA. Sub-circuit FBA consists of Resistors R1120,R1121, R1122, R1123 and R1124.

FIG. 40A Table Element Value/part number R1123 499k ohms R1124 499k ohmsR1122 6.65k ohms R1121 499k ohms R1120 1MEG ohms

Input node PF+ connected to series resistor [R1123+R1124] then toparallel resistors [R20||R21||R22] to the return node BR−. ResistorsR1120, R1121, R1122, R1123 and R1124 values are selected for a nominalinput voltage of 385-volts and output feed back voltage of 3.85. (Seeoscillograph G1FIG. 34) Resistors R1120, R1121, R1122, R1123 and R1124are shown in surface mount configuration but can be combined into twothru hole-resistors. Feedback output node PF1 is connected to node PF1of sub-circuit PFA (FIG. 23) or PFB (FIG. 24). Return pin BR− isconnected to BR− of PFA (FIG. 23) or PFB (FIG. 24). Nodes FBE and FBC itmay also be connected between nodes FM1 pin PRFM0 or PW1 pin PRFM0 ofcontrol sub-circuit PWFM (FIG. 33).

FIG. 40B output voltage feed back sub-circuit IFB

FIG. 40B is the schematic of the inventions isolated low voltage feedback network sub-circuit FBA. Sub-circuit IFB consists of ResistorsR900, R901 and R902, zener diode D900, Darlington transistor Q900 andopto-isolator U900.

FIG. 40B Table Element Value/part number U900 NEC2501 Q900 FZT705CT D900IN5261BDICT R900  1k ohms R902  4k ohms R901 40k ohms

Node OUT+ connects cathode of D900 to R901. Anode of diode D900 isconnected to series resistor R900 to base of Darlington transistor Q900.Resistor R902 is connected from base to emitter to Q900. Resistor R901connects to anode of opto-isolator U900 LED (light emitting diode) thecathode is connected to Q900 collector. Emitter of Q900 is the returncurrent path and connects to pin/node OUT−. Resistor R901 limits themaximum current to U900 internal light emitting diode to 20 ma. ResistorR902 shunts some of the zener leakage current from the base. Zener diodevoltage selection sets the converter output voltage a typical valuemaybe 48-volts. The zener voltage is the final desired output minus twobase emitter junction drops (1.4V). Once the OUT+ node reaches the zenervoltage a small base current biases Q900 into a conducting state turning“on” opto-isolator U900 internal LED. Resistor R900 limits the maximumbase current to Q900. Resistors R900 and R901 are selected to biasDarlington transistor Q900 collector current with nominal voltage acrossnodes OUT+ and OUT−. Change in voltage between OUT+ and OUT− modulatesthe opto-isolator U900 LED current in turn changing the base current ofU900 internal photo transistor. Phototransistor emitter is node FBEcollector is node FBC. Modulating the LED current is reflected asvariable impedance between FBC and FBE. This phototransistor may beconnected as a variable current source or impedance. When used withcontrol sub-circuit PFA (FIG. 23), PFB (FIG. 24) or (PWFM FIG. 33) thephototransistor is connected as a current shunt. Higher voltage appliedto OUT+ and OUT− nodes increases the feedback shunt current commandingthe control sub-circuit (See PFA (FIG. 23) or PFB (FIG. 24) or PWFM(FIG. 33)) to reduce the pulse-width or frequency. IFB accomplishes highspeed feed back due to the very high gain of the Darlington transistorand the rapid response of the internal converter stage(s) active ripplereduction and excellent load regulation are achieved.

FIG. 40C is the schematic of the alternate PFC isolated over voltagefeed back network sub-circuit IOVFB. Sub-circuit IOVFB consists ofresistors of R917, R938, R939 and R940, diode D911, Darlingtontransistor Q914 and opto-isolator U905.

FIG. 40C Table Element Value/part number U905 NEC2501 Q914 FZT705CT R938160k ohms R939  70k ohms D911 1N5261BOTCT R940  50k ohms R917  40k ohms

The output of the PFC at pin PF+ is connected to R917 then to collectorof Q914. Resistor R917 sets the maximum current to U905 light emittingdiode. Resistor R938 is connected from return node PF+ to zener diodeD911 cathode and R938. Resistor R939 is connected from return node PF−to zener diode D911 cathode and R938. Anode of D911 is connected towiper arm of adjustable resistor R940. One leg of R940 is connected tothe base of transistor Q914 the other to R939 and U905 LED anode andR939. Emitter of Q914 is connected to anode of U904. Adjustable resistorR940 sets the maximum or trip voltage before transistor Q914 is biasedon. Providing current to U905 LED. Phototransistor emitter is node FBEcollector is node FBC. Modulating the LED current is reflected asvariable impedance between FBC and FBE. This phototransistor is normallyconnected as a shunt to force the control element to a minimum output.This sub-circuit senses the boost voltage and feeds back to the PFC.Where excessive boost voltage forces the PFC to automatically reduce theboost voltage.

FIG. 41 output voltage feed back sub-circuit FBI

FIG. 41 is the schematic of the alternate low voltage feed back networksub-circuit FBI. Sub-circuit FBI consists of Resistors R81, R82 and R83,zener diode D80, NPN transistor Q80 and capacitor C80.

FIG. 41 Table Element Value/part number R81 1k ohms D80 Zener Voltage =(Desired Output-0.65 V) Q80 BCX70KCT C80 1000 pf R82  1k ohms R83 715kohms

Node OUT+ connects cathode of D80. Anode of diode D80 is connected tothrough resistor R83 to OUT− and resistor R82 to base of transistor Q80.Capacitor C80 is connected from base to pin OUT−. Capacitor C80 bypasseshigh frequency to noise to OUT−. Resistor R81 is connected from emitterof Q80 to node OUT−. Resistor R81 adds local negative feedback toreduces the effects of variation in transistor gain. Collector of Q80 isconnected to pin FBC. The return current node connects to pins FBE andOUT−. Resistor R82 limits the maximum base current protecting Q80.Resistor R83 shunts some of the zener leakage current from the base.Zener diode voltage selection sets the converter output voltage atypical value maybe 48-volts. The zener voltage is the final desiredoutput minus one base emitter junction drop (0.65-Volts). When the OUT+node reaches the nominal level reverse biased zener starts to conductinjecting a small base current into Q80. Biasing transistor into aconducting state. Change in voltage between OUT+ and OUT− modulates Q80collector current. During normal operation the zener diode is biased atit's knee thus small changes in voltage result in relatively largecollector current changes. When sub-circuit FBI used with controlsub-circuit PFA (FIG. 23), PFB (FIG. 24) or (FIG. 33) the transistor isconnected as a current shunt. Higher voltage applied to OUT+ and OUT−nodes increases the feedback shunt current commanding the controlsub-circuit (See PFA (FIG. 23) or PFB (FIG. 24) or PWFM (FIG. 33) toreduce the pulse-width or frequency. Sub-circuit FBI provides high-speedfeedback and gain to ripple components. With the rapid response of theinternal converter stage(s) active ripple reduction and excellent loadregulation are achieved.

FIG. 42 over voltage protection sub-circuit OVPL

FIG. 42 is the schematic of the inventions over voltage protectionembodiment sub-circuit OVP1. Sub-circuit OVP1 consists of SCR (siliconcontrolled rectifier) SCR1200, resistor R1200, capacitor C1200 and zenerdiodes D1200, D1202 and D1203.

FIG. 42 Table Element Value/part number SCR1200 MCR265-10 D1203BZT03-C200 (200 V) D1202 BZT03-C200 (200 V) D1200 IN4753 (5.1 v) C1200220 pf R1200 10.0k ohms

Input pin PF+ is connected to cathode of zener diode D1203, anode ofD1203 is connected to series zener diodes [D1202+D1200] then to gate ofSCR1200. Noise attenuation network of [R1200||C1200] is connected fromSCR SCR1200 gate to the return node BR−. Diodes D1102 and D1103 are both200-volt; D1101 is a 5.1-volt type the sum of the zener voltages set thetrip point of the OVP at 405-volts. Other trip voltages may beimplemented by selecting other zener diode combinations. Capacitor C1200and R1200 prevents leakage current and transients from accidentallytripping the OVP. In the event of very high AC line voltages or acomponent failure in a feed back loop (FIGS. 40A, 40B, 40C or 40) Theboost voltage may quickly rise increase to levels dangerous to theoutput switch or output storage capacitors. When the output boostvoltage of the at node PF+ rises above 405V, zener diodes D1203, D1202and D1200 conduct a small current into the gate of SCR1200 turningSCR1200 on. Turning SCR1200 on places a low impedance path across the ACline through the rectifier sub-circuit BR (FIG. 22). SCR1200 and bridgerectifier diodes must be selected to withstand the short circuitcurrents that may exceed 100 amperes until the input fuse opens. Thusquickly limiting the boost output voltage to a safe level. This circuitshould never operate under normal AC line voltages. By changing zenervoltages this sub-circuit would also be suitable for use in the acrossthe rectifier output to protect the load from an over voltage condition.Sub-circuits OVP1 shuts down the converter with out opening the linefuse. Sub-circuit OVP may be used in combination with OVP1 (FIG. 42A) asa fail-safe back up for critical loads.

FIG. 42A over voltage protection sub-circuit OVP1

FIG. 42A is the schematic of the inventions over voltage protectionembodiment sub-circuit OVP2. Sub-circuit OVP2 consists of SCRs (siliconcontrolled rectifier) SCR1001 and SCR1100, resistors R1101 and R1102,capacitors C1100 and C1101 and zener diodes D1100, D1102 and D1103.

FIG. 42A Table Element Value/part number SCR1101 S101E (Teccor) SCR1100S601E (Teccor) D1103 BZT03-C200 (200 V) D1102 BZT03-C200 (200 V) D1100IN4753 (5.1 v) R1100 16000 R1101 5.1 K ohms R1102 5.1 K ohms C1100 1200pf C1101 1200 pf

Anode of SCR1101 is node/pin CP18V+ that is connected to externalcontrol DC source. Return node BR− is connected to SCR1001 cathode andcapacitor C1100. Input node PF+ is connected to cathode of zener diodeD1103 and to series resistor R1100 then to anode of SCR SCR1102. Theanode of D1103 is connected to the cathode of D1102. The anode of D1102is connected to the cathode of D1100. The cathode of SCR1100 isconnected to the gate of SCR1101. The anode of D1103 is connected toseries zener diodes [D1102+D1100] then to capacitor C1100 then to thereturn node BR−. Capacitor [C1200||RR1200] prevents leakage current andtransients from accidentally tripping OVPB. In the event of very high ACline voltages or a component failure in a feed back loop (IPFFB FIG.40A, FBA 40B, IFB 40C or FBI FIG. 41) The boost voltage may quickly riseincrease to levels dangerous to the output switch or output storagecapacitors. When the output boost voltage of the at node PF+ rises above405V, zener diodes D1103, D1102 and D1100 conduct a small current intothe gate of SCR1101 latching SCR1101 on. Resistor R1100 provides holdingcurrent for SCR1101. Turning SCR1101 provides gate current to SCR1100,resistors R1100 and R1101 limits the gate current and provides the holdcurrent to SCR1100. With gate current to SCR1100 the SCR is turned onproviding a low impedance path from nodes CP18V+ to BR−. This actionremoves the regulated power to the main switch buffer and or PWMcontrollers PFA (FIG. 23) or PWFM (FIG. 33) and or buffer AMP (FIG. 29)thus turning off the main switch. The converter is held in an off stateuntil boost voltage PF+ through R1100 can not maintain the holdingcurrent of SCR1101. Typically power must be removed from the system toreset SCR1101. The minimum holding current of SCR1101 is typically 5-10ma. The action of OVPL quickly limits the boost output voltage to a safelevel. This circuit should never operate under normal AC line voltages.By changing zener voltages this sub-circuit would also be suitable foruse across the output rectifier to protect the load from an over voltagecondition. Sub-circuit OVP1 gracefully shuts down the converterrequiring manual intervention to reset the fault.

FIG. 42B is the schematic of the isolated output over voltage feed backnetwork sub-circuit OVP2. Sub-circuit OVP2 consists of resistors ofR970, R971, and R972, capacitor C970, zener diode D970, SCR SCR970,Darlington transistor Q970 and opto-isolator U970.

FIG. 42B Table Element Value/part number D970 1N5261BOTCT U970 NEC2501Q970 FZT705CT R970 160k ohms R971  10k ohms R972  22k ohms C970 200 pf

The output of the converter at pin OUT+ is connected to R972 and to thecathode of zener diode D970. The anode of D970 is connected to seriesresistor R970 then to base of Q970. Resistor R970 sets the maximum basecurrent to Q970. Resistor R971 is connected between the anode of D970and return node OUT− Anode of light emitting diode U970 is connected toresistor R972 then to OUT+. The cathode of U970 LED is connected to Q980collector. Emitter of Q980 is connected to return node OUT−. Zener diodeD960 sets the maximum or trip voltage before transistor Q970 is biasedon providing current to U970 LED. Application of voltage greater thanthe zener voltage of D970 injects a small base current into Q970.Transistor Q970 turns on the internal LED of U970 placingphototransistor in a conducting state and low impedance to pins OVC andOVC. External push-pull driver sub-circuit PPG (FIG. 43) is shut downimmediately by bringing pin PPEN high stopping the output stage.Sub-circuit OVP2 senses the output voltage and quickly feeds back to thepush-pull PFC. Where excessive boost voltage forces the PFC toautomatically reduce the boost voltage.

FIG. 42C is the schematic of the isolated output over voltage crowbarnetwork sub-circuit OVP3. Sub-circuit OVP3 consists of resistors ofR980, R981, R982, R983, R984 and R985, capacitors C980, C981 and C982zener diode D980, SCRs SCR980 and SCR981, Darlington transistor Q980 andopto-isolator U980.

FIG. 42C Table Element Value/part number D980 1N5261BOTCT SR980 S601E(Teccor) U980 NEC2501 Q980 FZT705CT R980 160k ohms R981 10k ohms R98222k ohms R983 51k ohms R984 1200 ohms R985 510 ohms C980 200 pf C9811200 pf C982 1200 pf

The converter output is sensed at pin OUT+ reference to pin OUT−. PinOUT+ is connected to resistor R982 and to the cathode of zener diodeD980. The anode of D980 is connected to series resistor R980 then tobase of Q980. Resistor R980 limits the base current to Q980. ResistorR981 is connected between the anode of D980 and return node OUT− toprovide a diode leakage current path. Anode of light emitting diode U980is connected through resistor R982 then to OUT+. The cathode of U980 LEDis connected to Q980 collector. Emitter of Q980 is connected to returnnode OUT−. Zener diode D960 sets the maximum or trip voltage beforetransistor Q980 is biased on providing current to U980 LED. Applicationof voltage greater than the zener voltage of D980 injects a small basecurrent into Q980. Emitter of opto-isolator U980 is connected to thegate of SCR981 and through [R984||C982] to return node BR−. TransistorQ980 turns on the internal LED of U980 placing phototransistor in aconducting state and supplying gate current to SRC SCR981 from theexternal 18-volt source connected to pin CP18V+. Network [R984||C982]prevents false triggering of SCR SCR981. The cathode of SCR SCR981 isconnected to the gate of SCR SCR980 and through [R985||C981] to returnBR−. With SCR SCR981 turned on gate current is provided to low voltageSCR SCR980. High voltage boost output is connected to pin PF+ resistorR983 supplies hold current to SCR SCR981 holding SCR SCR980 on. SCRSCR980 is selected for low hold current and ability to block the maximumboost voltage on PF+ SCR SRC980 anode is connected to pin CP18V+. SCRSRC980 cathode is connected to return pin BR−. SCR980 clamps the lowvoltage supply CP (FIG. 26) or CPA (FIG. 27). With the low supply helddown the gate drive to the main switch is disabled turning off theconverter. With the main switch Q1 (FIGS. 1, 3, 4) turned off holdupcapacitor C17 charges to applied AC line peak. With pin PF+ held nearline peak SCRs SCR981 will hold SCR SCR981 on until AC line power isremoved to the converter. Sub-circuit OVP3 senses the out ofspecification output voltage and quickly stop the converter therebyprotecting the load and converter with out generating destructivecurrents like OVP (FIG. 42).

FIG. 43 Push-pull oscillator sub-circuit PPG FIG. 43 is the push-pulloscillator sub-circuit of the invention. The current implementation usesa Motorola MC33025 pulse width modulator IC to generate the clocksignals to drive the push-pull output stage. Sub-circuit PPG consists ofU14 a two-phase oscillator, resistors R126, R130, R131, R132, R133,R134, R135, R136 and R137, capacitors C143, C136, C139, C140, C141 andC142.

FIG. 43 Table Element Value/part number U14 MC33025 R126 12k ohms R13010 ohms R131 10 ohms R132 47k ohms R133 10k ohms R134 100k ohms R135 15kohms R136 1.5 MEG ohms R137 15k ohms C136 0.22 uf C139 0.22 uf C140 0.22uf C141 0.01 uf C142 0.001 uf C143 .33 uf

The current implementation uses a Motorola MC33025 pulse width modulatorIC to generate the clock signals to drive the push-pull stage. But, anynon-overlapping two phase fixed frequency generator could be used. Pin 1of U14 is connected to [capacitor C143||Resistor R132] then to pin 3.Resistor R134 connects the internal 5.1-volt reference output of U14 pin16 to pin 1. Resistors R135 in series with R137 from 5.1-volt referenceto return node PPG0 form a voltage divider; the center is connected toU14 pin 2 placing pin 2 at 2.55-volts. Resistor R126 is connected fromU14 pin 5 to return node PPG0. Resistor R133 is connected from U14 pin 1to return node PPG0. Timing capacitor C142 is connected from U14 pins 6and 7 to return node PPG0. Resistor R126 and capacitor C142 set theoperating frequency of the internal oscillator. Timing resistor could bereplaced with a JFET, MOSFET, transistor, or similar switching device toprovide variable frequency operation. The drain of the transistor wouldbe connected to pin 5. The source would be connected to return nodePPG0. The variable frequency command voltage/current is applied betweengate and source. Capacitor C141 is connected from U14 pin 8 to returnnode PPG0. Capacitor C136 is connected from U14 pin 16 to return nodePPG0. Capacitor C140 is connected from U14 pin 15 to return node PPG0.Capacitor C139 is connected from U14 pin 13 to return node PPG0.Resistor R136 is connected from U14 pin 9 to return node PPG0. U14 pins10 and 12 is connected to return node PPG0. External power is connectedto node/pin PPG+ to PWM (pulse width modulator) IC U14 on pin 15 throughresistor R130 connected to the 18-volt control supply. Resistor R131connected to pin 13 of U14 and PPG+ provides power to the totem-polloutput stage. The power return line is connected to node PPG0. IC U14 isdesigned to operate at a constant frequency of approximately 20-600 Khzwith a fixed duty cycle of 35-49.9%. Resistors R135, R137, R133configure U14 to operate at maximum pulse width. A two-phase non-overlapping square wave is generated on pins 11 node PH2 and pin 14 node PH1and delivered to speed-up buffers AMP described in FIG. 29. Thetwo-phase generator is configured to prevent the issue of overlappingdrive signals that would null the core bias and present excessivecurrent to the switches. Sub-circuit PPG provides the drive to thepush-pull switches making efficient use of the NSME.

Although the present invention has been described with reference to apreferred embodiment, numerous modifications and variations can be madeand still the result will come within the scope of the invention. Nolimitation with respect to the specific embodiments disclosed herein isintended or should be inferred.

We claim:
 1. A converter comprising: an input power connection; acontroller; a feedback circuit; a drive; a low side drive driving a lowside switch; a high side drive driving a high side switch; an isolatordevice; a transformer; an output rectifier circuit; said outputrectifier circuit providing a signal to the feedback circuit; saidfeedback circuit providing a signal to the controller; said controllerproviding a signal to the low side switch and to the isolator device;said isolator device providing a signal to the high side switch; apositive input terminal of the input power connection connected to afirst node of a first N-Channel device; said positive input terminalfurther connected to a capacitor and to a resistor and further connectedto a first node of the isolator device; a second node of said isolatordevice connected to a second node of the first N-Channel device; saidtransformer providing isolated outputs from auxiliary windings to saidoutput rectifier circuit; said transformer further comprising a magneticelement operating in a non-saturated region (NSME); a capacitorconnected to a first terminal of said NSME; a third node of the firstN-Channel device connected to a first node of a second N-Channel deviceand a second terminal of said NSME; and a negative input terminal of thesource connected to a second node of the second N-Channel device and toa return node of the high side switch.
 2. The converter of claim 1,wherein said NSME further comprises a low permeability.
 3. The converterof claim 1, wherein the NSME further comprises a mixture of 85% byweight of iron, 6% by weight of aluminum, and 9% by weight of silicon,thereby providing a wide thermal operating range for the NSME.
 4. Theconverter of claim 1, wherein the low permeability has a range of one to550μ.
 5. The converter of claim 1, wherein the NSME is an air magneticelement.
 6. The converter of claim 1, wherein the NSME further comprisesa B-H curve characteristic ranging from B=1 to 10,000 gauss and H=1 to100 oersteds.
 7. The converter of claim 1 further comprising amodulating circuit to regulate an output signal from the NSME.
 8. Theconverter of claim 7, wherein the modulating circuit is a pulse widthmodulating circuit.
 9. The converter of claim 7, wherein the modulatingcircuit is a frequency modulating circuit.
 10. The converter of claim 7,wherein the modulating circuit is a combination frequency and pulsewidth modulating circuit.
 11. The converter of claim 1, wherein saidNSME further comprises a distributed magnetic element.
 12. The converterof claim 1, wherein the NSME is selected from the group consisting of:an air magnetic element; a molypermalloy powder(MPP) magnetic element; ahigh flux MPP magnetic element; a powder magnetic element; a gappedferrite magnetic element; a tape wound magnetic element; a cut magneticelement; a laminated magnetic element; and an amorphous magneticelement.
 13. The converter of claim 1, wherein the first node of thefirst N-Channel device further comprises a collector of a NPNtransistor, the first node of the isolator device further comprises acollector of an optical isolator, the second node of the isolator devicefurther comprises an emitter of the optical isolator, the second node ofthe first N-Channel device further comprises a base of the NPNtransistor; the third node of the first N-Channel device furthercomprises an emitter of the NPN transistor; the first node of the secondN-Channel device further comprises a drain of the N-Channel FET; and thesecond node of the second N-Channel device further comprises a source ofthe N-Channel FET.
 14. The converter of claim 1, wherein the controllerfurther provides a signal selected from the group consisting of avariable frequency variable pulse width signal, a variable frequencyfixed pulse width signal, a fixed frequency fixed pulse width signal,and a fixed frequency variable pulse width signal.
 15. The converter ofclaim 1, wherein the drive further comprises a switch drive gate bufferhaving an amplifier function, said buffer comprising a high speedN-Channel FET, a DC power source connected to a drain terminal of saidFET, an input signal to a gate of the FET, said input signal connectedto a base of a high speed PNP transistor which in turn is connectedbetween a source of said FET and ground, said PNP transistor having abase connected to a gate of the FET, a capacitor connected between abase of the PNP transistor and a collector of said PNP transistor, andwherein an emitter of the PNP transistor is connected to the source ofthe FET.
 16. The improvement of claim 1 further comprising a temperatureactivated switch connected in series with the DC power connection.
 17. Aconverter comprising: a power connection; a controller driven by thepower connection; a feedback circuit; a drive; a transformer; an outputrectifier; said output rectifier providing a signal to the feedbackcircuit; said feedback circuit providing a signal to the controller;said controller providing a signal to the drive; said drive providing asignal to an input of said transformer; said transformer furthercomprising a magnetic element operating in a non-saturated region(NSME); a capacitor connected to a second terminal of said NSME; andsaid capacitor connected to a return path of the controller.
 18. Theconverter of claim 17, wherein said NSME further comprises a lowpermeability.
 19. The converter of claim 17, wherein the NSME furthercomprises a mixture of 85% by weight of iron, 6% by weight of aluminum,and 9% by weight of silicon, thereby providing a wide thermal operatingrange for the NSME.
 20. The converter of claim 17, wherein the lowpermeability has a range of one to 550μ.
 21. The converter of claim 17,wherein the NSME is an air magnetic element.
 22. The converter of claim17, wherein the NSME further comprises a B-H curve characteristicranging from B=1 to 10,000 gauss and H=1 to 100 oersteds.
 23. Theconverter of claim 17 further comprising a frequency modulating circuitto regulate an output signal from the NSME.
 24. The converter of claim17, wherein the modulating circuit is a pulse width modulating circuit.25. The converter of claim 17, wherein the modulating circuit is afrequency modulating circuit.
 26. The converter of claim 17, wherein themodulating circuit is a combination frequency and pulse width modulatingcircuit.
 27. The converter of claim 17, wherein said NSME furthercomprises a distributed magnetic element.
 28. The converter of claim 17,wherein the NSME is selected from the group consisting of: an airmagnetic element; a molypermalloy powder(MPP) magnetic element; a highflux MPP magnetic element; a powder magnetic element; a gapped ferritemagnetic element; a tape wound magnetic element; a cut magnetic element;a laminated magnetic element; and an amorphous magnetic element.
 29. Theconverter of claim 17, wherein the controller further comprises a switchdrive buffer having an amplifier function, said buffer comprising a highspeed N-Channel FET, a DC power source connected to a drain terminal ofsaid FET, said controller providing an input signal to a gate of theFET, said input signal connected to a base of a high speed PNPtransistor which in turn is connected between a source of said FET andground, said PNP transistor having a base connected to a gate of theFET, a capacitor connected between a base of the PNP transistor and acollector of said PNP transistor, and wherein an emitter of the PNPtransistor is connected to the source of the FET.
 30. The improvement ofclaim 17 further comprising a temperature activated switch connected inseries with the DC power connection.
 31. A converter comprising: a powerconnection; a controller driven by the power connection; a feedbackcircuit; a drive; a transformer; an output rectifier; said outputrectifier providing a signal to the feedback circuit said feedbackcircuit providing a signal to the controller; said controller providinga signal to the drive; said drive providing a signal to an input of saidtransformer; and said transformer further comprising a magnetic elementoperating in a non-saturated region (NMSE).